We are living in a time of testing for the democratic ideal — that is often said and widely agreed.

I’ve come here today to talk about something less often discussed: solutions.

Previous generations overcame greater threats to democracy than those we face today: depressions, fascism, communism, nuclear terror. They acted successfully. Can we not do as well?

The challenge to democracy is presented acutely in the United States, but it is not unique to the United States. Authoritarian populist movements have shown strength in almost every European country. Sometimes they present themselves as right of center, as in France and Poland. Sometimes their lineage traces to the Left, as with the Five Star Movement in Italy and neocommunist parties across Europe. The differences matter. So do the commonalities.

The response to these challenges will vary from place to place, depending on local conditions and history. Important parts of the necessary response to Donald Trump will — as I’ll shortly argue — especially diverge from that to authoritarian movements in Europe. Yet as the threat shares many elements in common, including the more or less open backing of the Russian state under Vladimir Putin, so should the defense of democracy across the western world.

The solution begins with understanding of the sources of the problem. I see three — with a special bonus fourth uniquely active in the United States.

The first source is the slowdown of developed world economic growth since the year 2000, aggravated by two terrible financial crises, the US-centered mortgage crisis of 2008 and the Euro crisis of 2010. The US went 10 consecutive years without once seeing 3% growth in the decade between 2005 and 2015. Many European countries suffered extreme unemployment, especially youth unemployment.

That meant: less to go around for needs, public and private.

The second source is the aging of the baby boom generation. The huge cohort born in the decade and a half after World War II began to reach retirement age in 2010. Sixty-something boomers arrived at retirement poorer than they had expected in their peak earning years, back in the 1990s. Their later working years had been battered by two sharp stock-market busts, 2000 and 2008, and amid the severest housing-price collapse since the Great Depression.

That meant: the most politically powerful cohort in history would be demanding more at a time when less was available.

The third source is the rising level of ethnic diversity in all developed countries. As social scientists like Robert Putnam have taught us — and as political experience confirms — rising ethnic diversity reduces social solidarity. People trust and share less with those whom they perceive as different.

Which meant: less willingness to share at the very time that the baby boomers would claim more from a society with less to go around.

These three sources together generated the conditions from which the anti-Obama Tea Party would arise, and from which the authoritarian populists of Europe would gain strength. It’s unclear whether any actual Tea Partier — as opposed to an ironic counter-protester — ever actually carried a placard demanding: “Keep the Government’s Hands Off Medicare.” But if anyone did, it would not at all have been a foolish thing to say. The basis of the demand was not ignorance that Medicare, the US health insurance program for over-65s, is funded by government. The basis for the demand was keen awareness that Medicare is funded by the government — and that other claims on government, from other groups in society — could jeopardize Medicare’s finance. Remember, President Obama’s healthcare plan purported to finance itself in part by $500 billion in cuts to the future growth of Medicare. That’s a lot of money, even in the United States. Those funds would be redirected to cover the uninsured — a population that in the year 2010 was about 27% foreign-born. The ACA did not only redistribute from richer to poorer, and from older to younger. It redistributed from natives, mostly white, to immigrants, mostly nonwhite. In a multiethnic society, economic redistribution almost always implies ethnic redistribution.

In the late 20th century, “right” and “left” had argued over the proper role of government. In the 21st century, that old argument yielded to a new one over the proper beneficiaries of government. Parties of the left deserted their former supporters in the old industrial working class to champion new claimants upon the state. Parties of the right turned away from their origins as parties of enterprise to defend what the French call, “acquired rights.”

In the United States, and to a lesser extent the United Kingdom, these three mega-causes were joined to a fourth. The technology and finance booms since 1980 created individual fortunes of a kind not seen since before the First World War: vast agglomerations of private wealth in comparatively few hands. Since 2001 — and especially since the Great Recession — these small numbers of very rich people had received virtually all, sometimes literally all, the benefits of the whole society’s economic growth.

As of 2012, according to research by Emmanuel Saez and Gabriel Zucman, the richest 16,000 families in the United States — with an average net worth of more than $370 million each — held something over 11% of all the nation’s private assets … even as the share held by middle-income groups tumbled from something over 35% in the mid-1980s to under 25% in the aftermath of the Great Recession. Collapsing housing prices explain much of this story, but not all. Stagnating wages and the crackup of the two parent families squeezed saving and asset accumulation by ordinary wage-earners.

As wealth concentrates at the top, those who hold that wealth have become increasingly nervous about the risks of backlashes against them. Upper-class Americans express themselves in ever more anxious language — measuring their reasons for fear against the scale of their gains.

In January 2014, Silicon Valley venture capitalist expressed these fears in a letter to the Wall Street Journal:

“I would call attention to the parallels of Nazi Germany to its war on its ‘one percent,’ namely its Jews, to the progressive war on the American one percent, namely the ‘rich.’

“From the Occupy movement to the demonization of the rich embedded in virtually every word of our local newspaper, the San Francisco Chronicle, I perceive a rising tide of hatred of the successful one percent. There is outraged public reaction to the Google buses carrying technology workers from the city to the peninsula high-tech companies which employ them. We have outrage over the rising real-estate prices which these ‘techno geeks’ can pay.

“This is a very dangerous drift in our American thinking. Kristallnacht was unthinkable in 1930; is its descendent ‘progressive’ radicalism unthinkable now?”

Perkins’ letter was triggered by a controversy over on-street parking that had embroiled his ex-wife, the novelist Danielle Steel. Ms Steel had acquired 26 permits for herself, family, servants, and visitors. The city of San Francisco proposed a limit of four per household. Ms Steel argued her case in an oped for the San Francisco Chronicle. I’m sorry to report that article had provoked considerable mockery, not all of it good humored.

Contrary to Tom Perkins’ recollection, this is not actually very parallel to the origins of the Holocaust. Yet his mistake is important, and not only because it does credit to the amicability of his divorce from Ms Steel.

Perkins’ language is not actually all that unusual among people of his class. I could rattle off half a dozen comparisons of Barack Obama’s program to that of Adolph Hitler, not from talk radio hotheads, but from some of the most esteemed people in US business and finance: from the head of Blackstone, the world’s largest private equity firm; from the founder of Home Depot; and on it goes.

The special virulence and radicalism of Trumpist government in the United States, even as compared to its European counterparts, is owed to the junction between the fears of the Republican party base — that the claims of newcomers will displace their entitlements to Medicare and Social Security — and the nightmares of the Republican elite.

You may have encountered some form or another of the below quote: “A democracy cannot exist as a permanent form of government. It can only exist until the voters discover that they can vote themselves largesse from the public treasury.” It’s repeated often, sometimes attributed to Alexis de Tocqueville, sometimes to Aristotle, sometimes to a Scottish historian named Alexander Fraser Tytler. In fact, as best as historians can trace, it seems to have originated in an article in the Daily Oklahoman in 1953, written by a retired state legislator. Whatever its source, the thought is exactly upside down. From the overthrow of the Second French republic by Louis Napoleon in 1851, through the suppression of universal suffrage in the former Southern Confederacy after Reconstruction, through the fascist seizures that swept the struggling democracies established in Europe after the Treaty of Versailles, to the military coups in Latin America in the 1960s and 1970s — established democracies are most often toppled by their haves, not their have-nots. It’s the fear that the poor might pillage the rich that turns the rich against popular government.

Those who seek to defend democracy — democracy here meaning liberal democracy, constitutional democracy, a democracy as dedicated to the protection of individual freedoms, minority rights, and private property as it is to the principle of majority rule — those who seek to defend democracy must begin with a realistic assessment of the dangers democracy faces.

A second quote, this from the great historian of 18th century England, Lewis Namier: “The enduring achievement of historical study is an historical sense — an intuitive understanding — of how things do not happen.” Like Tom Perkins, too many would-be defenders of democracy terrify themselves by imagining the crisis of democracy as a reprise of events in Nazi Germany.

Hitler came to power after his country lost a world war that killed 2 million men and inured the survivors to random mass violence … after a defeat amid famine and social revolution … after an inflation that annihilated the remaining financial assets of the middle class … after a depression that plunged his country into destitution and hunger … in the throes of street battles that left hundreds dead and terrified German elites that a communist takeover loomed. Even then, it was all touch-and-go for Hitler: the crisis of 1932-33 could well have culminated in a military coup by a non-psychopathic authoritarian and a dictatorship that looked more like, say, Francisco Franco’s: repressive, but not bellicose or genocidal. It took a freakish sequence of events to bring a Hitler to power in an advanced bureaucratic state. They are not likely to recur.

But there are a lot of stops on the train line of bad before we reach Hitler station. It is those we need to monitor — and guard against.

I promised solutions, and so here are mine.

First: all developed countries need to restore encouragement of child-bearing and child-rearing to the top of their policy agendas. The aging of the population creates the background for the challenge to democracy, not only for the immediate economic reasons I described above, but also because older people are more prone to pessimism, even despair. For those who have passed the middle of our lives, our future is inescapably one of decline leading to extinction. What’s more natural than to project that outlook onto the society around us, to believe that our society’s best days must lie behind it since ours do? If the young are predisposed to radicalism, and the middle-aged to conservatism, the elderly seem biased to reaction. As their ranks have grown, the political mood has become more apocalyptic.

More immediately and tangibly, the birth dearth since the 1970s has biased all developed societies to high and rising levels of immigration to meet their labor market needs. We need young workers. We are not producing them. Ergo, we must import them.

The trouble is that the economies that need immigration most also happen to be the societies that can cope with immigration least.

During America’s previous mass immigration wave, 1880-1913, the average American woman bore more than 3.5 children. Immigrants joined a youthful, growing native population. They supplemented that population and were assimilated by it. Today, the average American woman bears 1.8 children. Native-born American women have even fewer children. In 2014, 23% of all the children born in the United States had immigrant mothers. No wonder that immigration is perceived as a challenge and threat by so many Americans: it now looks not like a supplement to a growing, youthful population, but a displacement and replacement of a shrinking, aging population.

Immigration is to native population increase as wine is to food: a good complement, a bad substitute.

Many have observed that the economies of the developed countries grew fast in the 1950s and 1960s, when the median age was under 30, and have grown much slower in the 21st century, with the median age nearing 40 in North America, and surpassing 45 in Japan and Germany. Older people take fewer risks, worry more about conserving what they have. What is true in the economy is true in the society too.

Of course it’s easy to remark that we should boost child-bearing, hard to do it. The reasons for the drop-off are deep — and the policy response deeply non-obvious. Countries like Franc and Sweden that have adopted the usual policy recommendations — more maternal leave, more daycare, more subsidies — have discovered that these benefits greatly encourage childbearing among first-generation immigrant women, but very little among native-born women.

How to do it is a topic for deeper discussion. The first step, however, is to agree that we must, not only to expand our economy, but even more to protect our democracy.

Faster economic growth would of course make everything easier. We hope that continuing recovery from the Euro-Atlantic crises of 2008-2010 will speed up growth. But growth only delivers political stability when the proceeds of growth are broadly shared, as they were in the thirty years after World War II. That has tended not to happen since 2000, and for different reasons in different parts of the developed world. In Europe, the young generation has been locked out from the benefits of growth by restrictions and taxes that discourage job creation and entry-level hiring. In the United States, work is easier to come by — but too often pays too little to buy the basics of modern life, especially adequate health coverage. Europeans who want work cannot find it; Americans who have work cannot live on it.

Europe needs a rollback of workplace regulation; the United States needs thicker social insurance guarantees, especially of their healthcare needs — and for the same reason: to build a society in which people can find worth in work, in which the system feels fair and worth defending, against which the fulminations of radicals and reactionaries both bounce in malign futility.

Third recommendation: the developed countries need to taper their immigration intake.

The debate over immigration is typically dominated by economists. Economists contend that immigration expands economies. That’s usually true. Economists often add that well-designed immigration raises native incomes. That’s less true: the models on which economists base these claims have a lot of problems, including most importantly that they do not measure the wage losses among native-born workers who quit the workforce altogether — as about one-tenth of American men in between 25 and 54 have done.

The wisdom of economists — that immigration can expand GDP — must be joined to that of social scientists, who can measure how it reduces trust and solidarity, and to that of political scientists, who can trace its power to destabilize and radicalize political systems. As Middle Eastern migration to Europe has quickened since over the past generation, so parties of the far right have gained strength, even before the Euro crisis of 2010. Geerts Wilders’ Freedom Party won 9 of 150 seats in the Dutch parliament in 2006; 24 in 2010; and now holds 33, the second largest bloc. Similar stories can be told of Austria, Belgium, France, Greece, and even Germany, the continent’s democratic bulwark, where a far-right party entered the Bundestag in 2017 for the first time in the history of the federal republic.

Canadians congratulate themselves on their exemption from the politics of Wilders and LePen and Trump. So far, that exemption has held. But the laws of social and political gravity in effect upon the rest of the planet apply in Canada too. The policy of the present Canadian government — to nearly double immigration numbers at what is almost certainly the peak of the post-2009 economic and employment cycle — seems reckless. As an immigration destination, Canada has many advantages over the United States and Europe: distance from immigration sources; land and sea borders that are unusually easily controlled; and also an unusual run of good luck — 2008-2009 was the first global economic crisis in recorded history that did not depress natural resource prices. Canada flourished economically while others struggled. The time may come when the tables are turned, and at that time the social kindling accumulated in the good years may prove every bit as combustible north of the 49th parallel as it has done to the south.

But possibly some good genie has fated that Canada will remain forever an exception. Congratulations to Canada if so. Enduring or not, the example is not exportable. Other countries will learn from their own experience, and that experience warns that defenders of democracy need to take more seriously the social instability courted by rapid and radical demographic change.

Let me here offer an analogy that may be clarifying. In the immediate aftermath of World War II, Western governments confronted huge communist parties on the continent of Europe; powerful and radical union movements in the English-speaking countries. How did political elites respond? They identified the grievances these radical movements battened upon — and they sought to assuage those grievances. They build social insurance systems to cushion the shocks of unemployment, sickness, and old age. They adopted demand-management fiscal policies to mitigate recessions and prevent depressions. They encouraged home ownership and university education to make a middle class out of the industrial proletariat. These measures progressively deprived communists and militants of any large constituency inside the western countries, isolating and marginalizing them.

Today again we confront radical social movements, in the form of authoritarian populism. Contemporary political elites lack the wisdom of their parents and grandparents. Rather than meet such grievances as can be met, severing rank-and-file from sinister would-be leaders, today’s elites refuse to yield an inch. The only political tactics they can imagine against the new authoritarian populists is direct confrontation, flecked with name-calling. Rather than divide these challengers to democracy, reconciling as many as possible, and dealing separately with the elements that cannot be reconciled, modern elites seem determined to treat them as a united mass, who can only be condemned, shunned, and repressed. The elites of 1950 wisely recognized that if only communists offered health insurance, then people who only wanted health insurance would have to become communists. In that same way, if we persuade voters that only fascists will defend their nation’s borders, then we will persuade many voters that they are fascists.

A fourth recommendation, this especially applicable to the United States. In the aftermath of the Great Recession, the United States needed a thicker social insurance net, especially with regard to healthcare. This, the Obama administration sought to deliver. Some might say — I would — that it over-delivered.

Obama’s own party, however, did not see things that way. They discounted their winnings and obsessed over an ever-lengthening wish list. What about early childhood education? Student loan forgiveness — no wait, free college for everybody! Raise the minimum wage to $12, on second thought $15. Medicare for all! So it went. Hillary Clinton ran in 2016 to the left of Barack Obama, and far to the left of the Hillary Clinton of 2008. Bernie Sanders ran to the left of Hillary Clinton. Meanwhile, the British Labour party has fallen into the hands of people to the left of Bernie Sanders — some of them literally unrepentant Stalinists.

At the moment when the center most needs strengthening, the ferment of politics seems to be bubbling further and further to the left.

This is problematic not only because such left politics are wrong on the merits, although I do believe they are. The leftward veering is dangerous because it intensifies the radicalization of the right — and especially of the formerly responsible right, the business right, the non-authoritarian, non-populist right. In 2016, Trump repelled much of the traditional leadership of the Republican party. He raised only about half as much as Hillary Clinton. Upon the release of the Access Hollywood recording on October 7, 2016, congressional and business leaders deserted him. Speaker of the House Paul Ryan severed his campaign connections with him. They expected Trump to lose. Many quietly wished for Trump to lose.

He did not lose. In office, Trump has proven surprisingly accommodating of traditional Republican economic concerns. While forward momentum on trade liberalization has ceased, Trump has not instituted new protectionism. He has not made good on his frequent threats to cancel NAFTA. He pushed to repeal Obamacare and reduce Medicaid coverage. He failed on that count, but his tax program looks healthier — and could not be more agreeable to the GOP donor class.  His party has become increasingly protective of him — and of mini-Trumps like Alabama Senate candidate Roy Moore.

What else can they do? As the Clinton-Blair neoliberalism of the 1990s dwindles into a reviled epithet, its place usurped by a more aggressive and assertive left politics, the business right feels itself without alternatives. Either make common cause with the authoritarian populists — or be exposed without protection to more radical redistributionism.

A more self-limiting politics would be a more effective and successful politics. Loose talk of revolution scares people who expect to be on the receiving end of that revolution — and drives them into reactionary alliances. Emmanuel Macron showed how a responsible centrism can split traditional conservatives from authoritarian populism. He ran the campaign Hillary Clinton could not or would not but anyway did not run, driving France’s National Front down below 34% of the vote. But the times are not bringing forth many Macrons.

Instead, the incentives are to play to ever more specialized constituencies, mobilized by ever more particular ideologies. When Elizabeth Warren told Netroots Nation in August, “We are the heart and soul of the Democratic party” — she was saying something true and important. So was Jeremy Corbyn in September when he repudiated from the platform not only the legacy of Margaret Thatcher, but that of Tony Blair, the most successful leader in Labour party history.

Sanders and Warren and Corbyn and their counterparts on the European continent may inwardly recognize some limits to their ambitions. They outwardly acknowledge none. By acknowledging none, they ratify the Mephistophelean bargain between normal conservatism and authoritarian populism: the Paul Ryan — Mitch McConnell — Donald Trump pact that offers tax cuts and deregulation as compensation for subversion of institutions and obstruction of justice.

All my recommendations today can really be summed up in one word: limits. Written constitutions are intended as limits, but written words acquire political meaning only when they are backed by an intention to enforce them — and a willingness to submit them. In a constitutional polity, the participants respect limits as a first principle. It’s often said: to live under law is to accept that the rules of the game matter more than its outcome. But that acceptance is always conditional. The players elevate rules over outcomes precisely because they all tacitly agree that the outcomes will never vary too far beyond certain understood bounds.

The United States today faces a constitutional crisis.

A president helped into office by a Russian espionage effort is today claiming impunity from the laws about obstruction of justice. Unlike Richard Nixon during Watergate, this president has not acted secretly. His wrongful acts were committed in spectacular public view — and are justified by more than one-third the country as a lesser evil than allowing their political opponents to hold power.

To check this onslaught will require the joint exertions of all committed to democracy and the rule of law. That will require concerted action by people who disagree about ordinary political issues. Sustaining that concert will require that Americans rediscover something lacking in their politics for a long time: the spirit of moderation. Not the moderation that is shy about its values. But the moderation that imposes self-restraint on the means by which those values are advanced.