President Trump on March 8. (Jabin Botsford/The Washington Post)

Earlier this month, President Trump gave lawmakers a week's notice that he was going to announce new steel and aluminum tariffs that Republican leaders vehemently opposed. Congress, which the Constitution gives power over tariffs, could have tried to stop the move. But congressional Republicans did nothing.

Now Trump is openly attacking special counsel Robert S. Mueller III's investigation in a way that suggests he may be trying (again) to fire Mueller. And congressional Republicans are apparently doing nothing.

The events of recent weeks have driven home what has been evident for some time — perhaps as far back as the 2016 presidential campaign — that Trump has neutered the Republican Party. Party leaders are afraid to do anything to cross him because he's much stronger with the party's base and has no loyalty to them. The past few weeks have demonstrated the potency of an unrestricted Trump and a party leadership that has basically no will to try to check his impulses.

Some Republican lawmakers have laughably suggested that protecting Mueller isn't in the cards because they can't imagine Trump actually firing the special counsel, who is investigating Russian interference in the 2016 campaign and whether the Trump team was involved. Sen. Orrin G. Hatch (R-Utah) said Monday that he is convinced that Trump won't do it “because I think it would be the stupidest thing that anybody could do.” Except that Trump already  has tried to do that very same “stupidest thing” — last summer. Only White House counsel Donald McGahn was able to stop him by threatening to resign.

Around the same time, Sen. Thom Tillis (R-N.C.) led an aborted effort to pass a bill that would have prevented Trump from firing Mueller. Tillis tweeted about that effort Monday but said there is no “imminent need to do it today or this week.”

House Speaker Paul D. Ryan (R-Wis.) also insisted Tuesday that Trump wouldn't do it, going so far as to say that he had received “assurances” that Trump wasn't considering it. And Senate Majority Leader Mitch McConnell (R-Ky.) has said something similar.

But the award for honesty goes to Senate Majority Whip John Cornyn (R-Tex.), who copped to the real reason for putting off or avoiding such legislation. “I don’t see the necessity of picking that fight,” Cornyn said, according to Politico.

Republicans know that resisting Trump comes with penalties. They still want to get things done in the (possibly short) time they have majorities in Congress, and that means they are going to sit on their hands and hope for the best when it comes to things such as a possible trade war sparked by the tariffs and such as Trump maybe trying to fire Mueller again.

But their assurances that Trump simply won't do that are foolhardy. Nothing in Trump's political past suggests that anything can be ruled out. And the idea that he won't do something he has already tried to do is ridiculous on its surface. Do they really think Trump has suddenly seen the error of his ways after trying to fire the special counsel in June?

Of course not. They just have no better excuse for not trying to protect Mueller. And Trump has backed them into a corner, rendering them subservient to him and his unpredictable whims.