If Tuesday’s congressional testimony by William Taylor, the acting United States envoy to Ukraine, is to be taken at face value — and no one in the Trump administration has yet denied a word of it — then it is now beyond doubt: President Trump placed his personal political future above the national-security interests of the United States. He did so at the expense of longstanding foreign policy, a critical international alliance and the stability of the global order — and he used hundreds of millions of taxpayer dollars to do it.

The nation has known the basic outlines of this story for weeks, thanks to the bravery of a C.I.A. whistle-blower and others. But in 15 pages, Mr. Taylor laid out with a stunning degree of detail the extent of Mr. Trump’s effort to extort Ukraine’s new president, Volodymyr Zelensky, to investigate former Vice President Joe Biden, a front-runner for the Democratic presidential nomination, and his son over supposed corruption.

You know it’s bad for the president when the only response the White House can muster is to sidestep the testimony and complain instead about “a coordinated smear campaign from far-left lawmakers and radical unelected bureaucrats waging war on the Constitution.”

Would that be the same Constitution that Mr. Trump referred to, in part, as “phony” just this week ? Also, “radical unelected bureaucrat” is a curious way to describe Mr. Taylor, who currently serves as Mr. Trump’s acting envoy to Ukraine and is a retired career civil servant and Vietnam War veteran who has served under both Republican and Democratic presidents.