Summon to mind the most memorable moments in television convention coverage:

George McGovern’s late-night speech to the nation in 1972 from a platform filled with his scowling party rivals.

Police clubbing protesters in Chicago during the 1968 Democratic convention.

Barry Goldwater proclaiming that “extremism in defense of liberty is no vice” in the San Francisco Cow Palace in 1964.

Senator Everett Dirksen literally pointing a finger at former Governor Thomas Dewey in 1952 to accuse him of leading Republicans “down the road to defeat.”

Great TV! But terrible politics.

Contrast these exciting events to, say, the first night of the Republican convention of 2000. Wedged between country rock medleys, Ben Stein interviewed a former Miss America about the excellence of the Texas public schools under George Bush. Next came three video “profiles in compassion.” Followed by a speech by a Latino single mother. Followed by a performance by inner city elementary students. Followed by hyperglycemic shock.

Terrible television—but better politics.

Since the 1970s, the parties have become much more skilled and sophisticated at running their shows. They adjusted their rostrums to look more appealing on television: red, white, and blue gave way to salmon, cream and aquamarine. Speeches have been shortened; politicians have ceded place to celebrities and telegenic ordinary folks, all intended to create a cult of personality around the ultimate nominee that would be almost sinister if it did not so often absurdly backfire. (“I’m John Kerry, and I’m reporting for duty!”)

The talking heads on television blame the parties for mounting a boring show. The talking heads should blame themselves: The parties made the conventions dull in self-defense, because anything exciting can and will be used against them.

It does not have to be this way. The conventions could be made useful, interesting and important again. That will require some reinvention. But the conventions have been reinvented before to adapt to the needs of their time, and they can be reinvented again.

The story of the American convention is a story of firsts.

Franklin Roosevelt in 1932 was the first nominee to address a convention in person, putting an end to the old weary fiction of the reluctant candidate.

The Republican convention in 1952 nominated Dwight Eisenhower on a single ballot–the first such victory for anyone other than a sitting president.

The Democratic convention of 1972 was the first where a majority of the delegates were chosen in primaries—that is, by direct vote of party members.

This year there will be another first: For the first time since John F. Kennedy in 1960, a candidate will deliver his acceptance speech off-site. Barack Obama will accept the Democratic nomination not in the convention hall, but in a nearby football stadium. Kennedy’s decision to shift across the street from a small sports stadium was a last-minute decision by a candidate who arrived at his convention uncertain of success. Obama’s is a carefully advance-planned exercise in image-making.

Add these changes together, and you reveal an institution in evolution. The convention has ceased to be a decision-making body, and has become a giant stage set for a previously chosen candidate to speak directly to the nation. Sooner or later, somebody was bound to wonder: Is this really the best possible stage set?

If Barack Obama’s football stadium speech is perceived as a success, expect imitators: Why not an acceptance speech from the porch of a candidate’s humble boyhood home? Standing beside the Liberty Bell? In front of a shuttered factory? On the deck of a decommissioned battleship? From a living room decorated in warm peach tones? The possibilities are as wide as an image-maker’s imagination—which is to say, very wide indeed.

This trend may take a while to materialize. It may never materialize at all. But if it does take form, it will not be a new practice. It will be a reversion to an old practice, the pre-1932 practice of the nominee accepting his nomination far from the convention site. Having first ceased to be a decision-making body, the convention will now cease even to be much of a stage show.

(Let’s hope that the hypothetical renewed practice of off-site nomination acceptance begins more auspiciously than the previous practice did. The first words spoken by the first candidate to address a convention in person were, sad to say, at best seriously misleading. Franklin Roosevelt opened his 1932 speech in Chicago by apologizing for the delayed arrival of his plane from New York, saying: “I regret that I am late, but I have no control over the winds of Heaven and could only be thankful for my Navy training.” Roosevelt had served as—civilian—assistant secretary of the navy from 1913 to 1920, but had never received anything that could remotely be described as “Navy training.”)

Should future nominees follow Obama’s example, the massive media attendance at party conventions will dwindle, for the modern media go where the candidates go. The conventions, once so riveting, will drop below the media horizon into quiet and obscurity.

And yet—the conventions will continue to meet. They will have to, and for more or less the same reason that the Electoral College continues to meet: The nomination of a candidate is a legal as well as a political act, and the parties have to go through the formalities that make a nomination legal.

So the 2,000 or so Republican delegates and the 4,000 or so Democrats will carry on gathering every four years, in forums probably increasingly severed from the nominee’s formal acceptance speech, and with less and less press attention to their doings. The pundits will lament this loss of function—and the attending loss of airtime for themselves. But the loss is also an opportunity.

A party convention is the one time in four years when an American political party’s talents, its activists, and its donors are all gathered in one place—and it is the single time and place where you are least likely to hear a serious discussion of party policy and party plans. Right now, this vacuity is forced upon the parties. The last thing they want to do is engage in candid discussion and self-criticism surrounded by thousands of journalists waiting to pounce on any poorly phrased thought or ill-judged word.

But what if the journalists were absent? Not because they were banned, but because they did not bother to show up?

Party conventions could then discover a new purpose as showcases for emerging talent. With the candidate speaking in front of Mount Rushmore or wherever, the party’s next generation and second-tier figures could regain the convention microphones that have been progressively removed from them over the past three decades.

Sitting governors could be given platforms to detail their records in their states. Promising younger officials could participate in panel discussions and debates—and take questions from party members across the country. Right now, the parties are too busy staging a show for the whole country to tolerate any risk that some second-tier political figure might bore the audience or stumble into some off-message mistake. But with the press voluntarily absent and the voting public’s attention fixed elsewhere, mistakes would become less disastrous.

This year, for example, Republicans are worrying about the weakness of the party’s bench strength. Many Republicans see a possible future leader in Louisiana governor Bobby Jindal—but that opinion is based on favorable articles in opinion magazines and very occasional appearances on television or at party events. One way to check him out would be to give him a speaking slot at the Minneapolis convention—but that decision will be subordinated to the convention’s other and more pressing business of highlighting the presidential and vice-presidential nominees.

Take away that business, though, and there would be plenty of room not only for a keynote address by a leadership-selected favorite, but for substantive interactive discussion with rising talents like Governor Jindal—and Governor Tim Pawlenty of Minnesota and Governor Sarah Palin of Alaska and other bright new lights, enabling Republican activists to better make up their own minds about potential future leaders.

Instead of formal oratory, there could be question-and-answer sessions with every one of the party’s incumbent governors and panel discussions with congressional leaders. Instead of wandering around downtown Denver or Minneapolis with little to do, delegates could be offered opportunities to join themselves in moderated discussions or to hear serious briefings by invited policy experts. Today’s delegates are not the delegates of the 1920s or 1950s: They are hard-working, highly educated community leaders, and they want a more important role than that of extra hands for somebody else’s extravaganza production. Of course they enjoy the drinks and the fun. But they also want to engage in purposeful, public-spirited activities in the daylight hours before the show begins—and the withdrawal of the cameras from the convention creates the perfect opportunity to offer them purposeful activities.

The tightly orchestrated debate over the platform—always carefully stage-managed lest well-organized activists embarrass the candidate—could be dispensed with altogether, replaced by genuine substantive discussions undistorted by the need to arrive at some anodyne consensus. Delegates could hear discussions led by policy experts about the issues the next administration will face.

Events like the (left-wing) Netroots Nation convention, the (right-leaning) Conservative Political Action Conference, and the non-partisan Renaissance Weekends give a sense of what these party conventions of tomorrow could be. These non-party events treat their attendees with respect and seriousness: as participants, not as props; as people to be heard, not to be herded.

Let’s have no nostalgia and regret for the convention as it used to be. Those who actually attended the old conventions had little use for them, as H.L. Mencken reminds us in this dispatch from the chaotic Democratic convention of 1924:

“There is something about a national convention that makes it as fascinating as a revival or a hanging. It is vulgar, it is ugly, it is stupid, it is tedious, it is hard upon both the higher cerebral centers and the gluteus maximus, and yet it is somehow charming. One sits through long sessions wishing all the delegates and alternates were dead and in hell—and then suddenly there comes a show so gaudy and hilarious, so melodramatic and obscene, so unimaginably exhilarating and preposterous that one lives a gorgeous year in an hour.”

The show is long over. It was fatally wounded by the shift to open primaries and finished off by the imperatives of television. But even so, thousands of the most active Democrats and Republicans in America still agree to gather in one spot for public purpose every four years. They are doing something useful and important for American democracy—and the opportunity is there for them to do something more useful and important still. The era of the show business political convention is all but over. The era of the working political convention is waiting to begin.