Mitt Romney. Photo: Mario Tama/Getty Images

Mitt Romney announced Wednesday he will vote to convict President Trump on charges of abuse of power. Trump now becomes the first president in American history to be recommended for removal from office by a senator of his own party.

One of the historic ironies of the Trump era is that the two most powerful blows to his presidency have been struck by the two Republican presidential candidates who preceded him. In 2017, the 2008 nominee, John McCain, dealt a final and fatal blow to Trump’s attempt to repeal Obamacare. And now the party’s 2012 standard-bearer will vote guilty on impeachment.

Does Mitt’s vote matter? Yes, quite a bit. “Partisanship” is a commonly used heuristic for journalists and many voters who don’t follow politics closely. Trump’s defenders have dismissed impeachment as a partisan exercise, and while Romney’s vote will not stop them from saying it, it will provide an easy rebuke to those who do. Romney is not an obscure Republican, and not a moderate one, either.

His support is likely to embolden Democrats, too. Joe Manchin, senator from deep-red West Virginia, has withheld his position, and now has more cover to convict. The House will likewise have more public support in its continued investigation into scandal.

Romney has also secured his own fascinating place in the history books. As Massachusetts governor, he helped craft the first universal insurance reform in any state, which served as a model for Obamacare. He swung far to the right in an attempt to placate the anti-government mania that took hold in his party, eventually renouncing the very ideas he had pioneered. His lonely vote to convict Trump — a vote that will open no avenues of future advancement, and which will instead expose him to risk of defeat in Republican Utah — may be the capstone of his career.

The furious response he is provoking merely underscores that his announcement is anything but trivial. The Conservative Political Action Conference has already voted this week to ban him from the premises, merely for having the temerity to vote to hear John Bolton’s testimony. Donald Trump, Jr. is calling for his expulsion from the party. And President Trump tweeted a video attacking Romney as “slick,” and “slippery,” attempting to “infiltrate” Trump’s administration, “posing” as a Republican:

As Romney tells McKay Coppins, “Corrupting an election process in a democratic republic is about as abusive and egregious an act against the Constitution — and one’s oath — that I can imagine. It’s what autocrats do.” There is no reason to believe he has any motive for his action other than what he says — to defend democracy.

This post has been updated.