Presidents Trump and Nixon. (Office of the President)

After a month of shifting defenses over impeachment—from “there was no quid pro quo” to “we do that all the time—get over it!”—it’s finally come to this: pleading incompetence. Don’t worry, the Wall Street Journal suggests in its lead editorial, the president is too much of a bungler to pull off any high crimes.

“It may turn out that while Mr. Trump wanted a quid-pro-quo policy ultimatum toward Ukraine, he was too inept to execute it,” the WSJ opines. That’s supposed to let the president off the hook; after all, “impeachment for incompetence would disqualify most of the government, and most Presidents at some point or another.”

If this is the best they’ve got, it doesn’t look good for President Trump. Incompetence is no defense when it comes to high crimes and misdemeanors. The Nixon crew botched most of the schemes it undertook, from the Watergate caper to the attempt to audit the president’s political enemies. That didn’t save Richard Nixon from being driven from office via the impeachment process.

True enough, President Trump’s pratfalling management style has so far limited his ability to commit abuses. For example, Special Counsel Robert Mueller’s report suggests that the president isn’t any good at obstruction of justice: his “efforts to influence the investigation were mostly unsuccessful…largely because the persons who surrounded the president declined to carry out orders or accede to his requests.” Even Corey Lewandowski had enough brains not to help him out by passing messages to his estranged attorney general, Jeff Sessions.

It’s also true that Richard Nixon was a lot more on the ball than Donald Trump. You couldn’t just steal stuff off the 37th president’s desk and assume he’d forget about it. If Nixon told you to break into into the Brookings Institution and take their copy of the Pentagon Papers, you at least had to come up with a plan—in this case, firebombing the think-tank as a distraction from the burglary—even if you never carried it out.

Moreover, Nixon had enough sense to know that the “smoking gun” tape—which revealed that the president scheming to get the CIA to quash the Watergate investigation—was damning, and to sit on it until the very end. Trump, on the other hand, was apparently convinced that the July 25 call readout, where he asks President Zelensky to “look into” the Bidens, would exonerate him.

And let’s not get carried away praising the Nixon crew’s steely-eyed competence. These “were not very bright guys, and things got out of hand,” as Hal Holbrook’s “Deep Throat” put it in All the President’s Men. Nixon, too, surrounded himself with screw-ups and repeatedly found his plans frustrated by bureaucratic intransigence. The “Plumbers” were anything but a model of competent tradecraft. The Nixon team had to set up the unit in the first place because the official state security agencies—the “deep state,” if you like—were reluctant to carry out black bag jobs for presidents.

Yet repeated inability to consummate high crimes didn’t save Nixon from being forced out under threat of impeachment. The second article of impeachment against him, passed by the House Judiciary Committee in July 1974, focuses on abuse of power, including his attempts to misuse the CIA and turn the IRS against his political rivals. But Nixon never managed to get the CIA to stop the Watergate investigation, and the administration’s effort to “screw our political enemies” with IRS audits was a total failure. IRS commissioner Johnnie Walters flatly refused to carry out the scheme. Even so, attempting to corrupt the IRS was the first charge listed in Nixon’s second article of impeachment.

Impeachment’s purpose, constitutional scholar Greg Weiner explains, is “prophylactic,” not punitive: to protect the body politic from officials whose conduct presents an unacceptable risk. Nowhere is it written that you have to wait until the abuse is actually completed and the damage has been done.

Gene Healy is a vice president at the Cato Institute and author ofIndispensable Remedy: The Broad Scope of the Constitution’s Impeachment Power.