This will not stand.

President Trump performed his latest impersonation of a Third World strongman, firing FBI Director James B. Comey late Tuesday in ham-handed fashion as it was becoming clear that the FBI probe into Trump’s ties to Russia, which Comey was overseeing, was becoming a bigger problem for Trump while new testimony exposed dubious behavior by the president himself.

The sacking brought immediate outrage and obvious comparisons to President Richard Nixon’s Saturday Night Massacre, when the scandal-engulfed president ordered the Watergate prosecutor fired in a doomed attempt to keep that probe from ensnaring him. Trump, like Nixon, will fail, for a simple reason: The institutions he is assaulting daily are stronger than he thinks. His autocratic instincts have been checked every step of the way. Trump will, inevitably, be spanked again.

He attempted a variant of the “Muslim ban” he spoke of during the campaign, ordering a halt to travel by people from certain Muslim-majority nations. He was shot down in court.

He ominously questioned the legitimacy of “so-called” judges because of the ruling and said they should be blamed for terrorist attacks, while his White House said his authority “will not be questioned.” The courts begged to differ; his revised travel ban, too, is snarled in court.

He recklessly escalated tensions with North Korea and Iran and snubbed a key ally in Germany’s Angela Merkel. But cooler heads in the Pentagon and the State Department have calmed jittery allies and restored some measure of stability, conveying to them that Trump is not really in charge.

[If Trump fired Comey over Russia, he must go]

He injected himself into the French presidential elections with his praise for far-right candidate Marine Le Pen — and French voters rejected her by 2-to-1, following Dutch voters’ rejection of another far-right populist in the Trump mold.

He released a budget that slashed major government functions and domestic programs. But American public opinion has turned sharply against Trump, making it easier for Democrats to oppose him. In the spending bill that Congress passed last week, Democrats successfully repelled Trump’s border wall, deportation force and cuts to Planned Parenthood, the National Institutes of Health, the Environmental Protection Agency and more.

The plain truth is Trump’s clumsy assaults on democratic norms are being resoundingly rejected. The Cook Political Report is already talking about the possibility of a “midterm wave” against Republicans, and it shifted ratings in 20 House races — all in Democrats’ direction. At town-hall meetings, House Republicans who were badgered by the White House into voting for “Trumpcare” last week are already backpedaling.

At Monday’s hearing on the Trump administration’s ties to Russia, only six Republicans spoke (versus nine Democrats) and not one of them attempted a real defense of the president’s actions on disgraced former national security adviser Michael Flynn and Russia. Sen. Lindsey Graham (R-S.C.), the panel’s chairman, openly mocked Trump’s claims that the election hacking might not have been done by Russia but by a “400-pound guy sitting on a bed or any other country.”

Many of us feared during the campaign that Trump would be a threat to democracy, operating outside the Constitution, using demagoguery to turn white Americans against immigrants and religious and racial minorities. That hasn’t happened, though not for lack of trying on Trump’s part. His instincts are authoritarian, but the Trump presidency has been one pratfall after another. He has proved to be a blundering bully and an inept autocrat.

[Comey’s firing isn’t like the ‘Saturday Night Massacre.’ It’s pretty straightforward.]

At a single White House briefing Monday, the questioning revealed all manner of disarray. Conservatives, one questioner noted, were worried that the White House is “woefully behind” in filling administration posts and judicial vacancies. The education secretary and other senior administration officials weren’t even aware of a signing statement Trump issued on historically black colleges. Trump’s political website had, until this week, called the travel ban a “Muslim” ban even as the administration insisted it wasn’t. And 30 days into the 90-day period Trump’s opioid commission has to issue a report, no members of the commission have been named.

Now we may have the clumsiest moment yet of this presidency. Deputy Attorney General Rod J. Rosenstein, who had a sterling reputation when he was confirmed two weeks ago, instantly turned himself into a Trump stooge — Trump’s Robert Bork, to continue the Nixonian parallel — Tuesday evening. Questions about Comey’s performance are legitimate, but the timing of the firing, a day after a damaging hearing about Trump’s Russia ties, left the clear impression this was all about killing the FBI’s Russia probe.

Rosenstein has one chance to rehabilitate his reputation: He can name a special prosecutor to continue the probe. If he doesn’t, the wave of rebellion against Trump so far will become a tsunami, and it will swamp Trump’s protectors in the polls.

This president may think himself unassailable, but Americans are seeing him for what he is: a tin-pot tyrant.

Twitter: @Milbank

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