After months of insisting Donald Trump committed no wrong on his “perfect” call, Republicans have found their way to the inevitable endgame: arguing that the president is above the Constitution that he is sworn to uphold.

For months, Trump’s defenders claimed he never conditioned the release of military aid on Ukraine’s announcement of investigations into Joe Biden and Russian conspiracy theories, as alleged in the articles of impeachment. Trump’s legal team opened their argument on Saturday by declaring that no witness heard Trump link the aid to Ukraine’s manufacturing of dirt on Biden. But on Sunday, the nation learned that former National Security Adviser John Bolton heard the president admit he’d done just that.

For a moment, the president and his allies seemed flummoxed. Trump issued a series of tweets asserting that he “NEVER told John Bolton that the aid to Ukraine was tied to investigations into Democrats, including the Bidens.” Fox News began frantically suggesting that Bolton, of all people, was a secret agent of the left-wing “deep state.” On Monday, Trump’s lawyers resumed their defense in the Senate by arguing that there was no evidence of a quid pro quo in the “House record,” as if the nation remained ignorant of the Bolton account, which appeared on the top of every newspaper, website, and newscast.

But, apart from challenging credulity, the response created an obvious problem for Trump and his supporters: It amounted to a compelling argument for bringing Bolton, and even the president himself, before Congress to give sworn testimony, so as to allow the senatorial jury to decide who was telling the truth.

That, we know, is the last thing Trump or Mitch McConnell want.

On Monday night, Alan Dershowitz broke with Trump’s other defenders by acknowledging the existence of Bolton’s account, and went on to offer an audacious way for Trump to escape its import. The president, Dershowitz said, should be acquitted even if he engaged in the very corrupt scheme alleged in the House articles, because, “Nothing in the Bolton revelations, even if true, would rise to the level of an abuse of power or an impeachable offense.” This, Dershowitz argued, is because such audacious corruption is not sufficiently “crime-like.” The argument, though absurd, was met with relief by the president’s defenders in the Senate, who embraced it with relief and enthusiasm.

By Wednesday morning, Senator John Cornyn, the second ranking Republican, was taking Dershowitz’s argument even farther, declaring that, after reviewing the House’s investigatory record, he had concluded the “[e]vidence is undisputed,” rendering “[m]ore witnesses... unnecessary.” That is: Sure, he did it. So what?

This afternoon, during the trial’s question-and-answer session, Dershowitz returned to the Senate floor to offer a capstone to the president’s new defense, echoing the argument famously offered by Richard Nixon: “When the president does it, that means that it is not illegal."

In Dershowitz’s update of Nixon’s maxim, a president can be impeached only if he acts solely from “corrupt motives.” Thus, he said, if a president thinks “I want to be elected. I think I’m a great president. I think I’m the greatest president there ever was. If I’m not elected the national interest will suffer greatly,” then anything goes.

So, if Trump believes America needs him, it is OK for him to coerce an ally at war with Russia into announcing a fake investigation of a domestic political opponent by withholding critical military aid duly appropriated by Congress.

It was a remarkable display of legal audacity by the former Harvard professor, and, if accepted by a majority of the Senate, will indeed provide a rationale for concluding the trial and acquitting Trump without hearing Bolton’s testimony. But it will also mark the final surrender of the legislative branch to the executive, and the end of the American system of government and way of life, as we have known them.

If Trump and GOP senators claim this “victory,” it is one that the Republican party and the president may well come to regret in November. This is because, far from providing Trump with the vindication he so desires, an acquittal in the Senate will amount to an admission that Trump engaged in the very corrupt scheme alleged by the House.

Therefore, if GOP senators vote to excuse Trump’s now open and notorious misconduct, they will join Mick Mulvaney in declaring that presidential corruption is no crime at all, and demanding that the nation “get over it.” It remains to be seen whether voters will agree to do so.