During the hearing, committee Republicans continued to make fools of themselves, as epitomized by Comer loudly insisting that he has built a "mountain of evidence" against Biden when in fact — as Republican lawyers and experts have admitted — he has failed to erect even a molehill. Every item of "evidence" cited by Comer has disintegrated in public view.

Indeed, the impeachment hearing presented no fact witnesses at all — perhaps because the witnesses previously brought forward have either failed to testify as advertised or been discredited in advance.

There was that mysterious but "very credible" witness to supposed Biden corruption who "disappeared," according to Comer. But Gal Luft turned out to be a fugitive who had been indicted last year by the Justice Department on a variety of felony charges. There was that former partner of Hunter Biden, who was expected to testify about Joe Biden's illicit role in his son's business affairs. But Devon Archer said that Joe Biden had done nothing to assist Hunter's enterprises. There was that FBI document purportedly showing that Joe Biden had accepted a bribe, which was merely a form used by the bureau to record unverified source information, and otherwise meaningless without actual proof — of which there is none. And so on.

None of these squibs and duds have discouraged Republicans on the committee from uttering outrageous lies, protected by their privilege as House members. Rep. Nancy Mace (R-SC) declared that "we're talking about bribery," without offering any evidence of same. Rep. Byron Donalds (R-FL) displayed a fabricated screenshot of a text message from Hunter Biden to his uncle James Biden. Donalds then falsely suggested that the message revealed a scheme to split money from foreign sources, when it was nothing more sinister than Hunter complaining about his personal financial woes.

Why are Republicans pursuing impeachment without evidence of any wrongdoing by the president? As he often does, Trump said the quiet part out loud when he told Megyn Kelly the other night that this charade is occurring simply because he was impeached twice. "I think had they not done it to me... perhaps you wouldn't have it being done to them," he said, coyly omitting his own role in directing the Biden impeachment.

Under the Constitution these Republicans all swore an oath to uphold, that doesn't cut it. A president cannot be impeached because someone offended Donald Trump. A president cannot be impeached because Republicans want to win an election next year. A president cannot be impeached because the House majority wants to divert attention from Trump's indictments and their own incompetent stewardship of a government that is about to be shut down.

A president can be impeached only for treason or other "high crimes and misdemeanors."

There is no reason to believe Joe Biden has committed any such offenses — and ample reason to suspect his persecutors are consciously lying every time they smear him. The story of this impeachment is not his perfidy, but theirs.

Joe Conason is editor-in-chief of The National Memo, author of several books including two New York Times bestsellers, and editor-at-large for Type Investigations.