Even for the small band that sustained the phony controversy until now, the birth certificate so-called issue ends today.

Any last lingering doubts that maybe, perhaps, a pregnant Stanley Ann Dunham in the summer of 1961 boarded a propeller plane from Honolulu to Los Angeles, then from Los Angeles to New York City, then from New York City to Gander, then from Gander to London, then from London to Nairobi — and then repeated the trip backward a few weeks later — all so that her baby could acquire Kenyan nationality — those doubts are definitively squelched, as they should have been three years ago.

Now the more haunting question: How did this poisonous and not very subtly racist allegation get such a grip on our conservative movement and our Republican party?

I know there will be Republican writers and conservative publicists who will now deny that birtherism ever did get a grip. Sorry, that’s just wrong. Not only did Trump surge ahead in Republican polls by flaming racial fires — not only did conservative media outlets from Fox to Drudge to the Breitbart sites indulge the birthers — but so also did every Republican candidate who said, “I take the president at his word.” Birthers did not doubt the president’s “word.” They were doubting the official records of the state of Hawaii. It’s like answering a 9/11 conspiracist by saying, “I take the 9/11 families at their word that they lost their loved ones.”

Yet even now, the racialist aspect of the anti-Obama movement has not subsided. Trump has moved from the birth certificate to questioning the president’s academic qualifications for the Harvard Law School. Trump himself was a troubled student (at one point he attended a military school) who nonetheless gained admission to Wharton. His father’s wealth and business success cannot have hurt with that application. Yet he feels himself qualified to pronounce on who is and who is not smart enough to attend Harvard Law. Barack Obama graduated magna cum laude. (And to anticipate a new line of attack — yes, Harvard Law School exams were blind-graded.) He was elected editor of the law review. And his classmates, left and right, universally admired his abilities.

I wish it were otherwise, but it does seem that these racialized attacks on Obama have exacted a toll on him. But they also have exacted a toll on the opposition to Obama. The too-faint repudiation of birtherism by regular Republicans has shaped not only the Obama brand, but also the Republican brand. It was not only white people who heard the implied message about who counts and who does not count as a “real American.”

I write as an opponent of virtually every major and minor action of this administration. Republicans should be fighting this president on policy, not winking at those who use race as a weapon. It’s worth recalling the generous words of John McCain on election night 2008:

[T]hough we have come a long way from the old injustices that once stained our nation’s reputation and denied some Americans the full blessings of American citizenship, the memory of them still had the power to wound. A century ago, President Theodore Roosevelt’s invitation of Booker T. Washington to dine at the White House was taken as an outrage in many quarters. America today is a world away from the cruel and frightful bigotry of that time. There is no better evidence of this than the election of an African-American to the presidency of the United States. Let there be no reason now for any American to fail to cherish their citizenship in this, the greatest nation on Earth.

And those who imagine that they somehow enhance the value of that citizenship by belittling the American-ness of their president — they not only disgrace the politics they uphold, but they do damage that will not soon be forgotten by the voters a revived Republicanism must win.