Sen. Mitt Romney, R-Utah, speaks to reporters after a classified members-only briefing on Iran on Capitol Hill in Washington, May 21, 2019. Credit: Patrick Semansky | AP

Not since they strapped Seamus in his dog crate to the roof of the family car has a member of the Romney household been this distressed.

Mitt Romney has watched with varying degrees of displeasure as President Donald Trump turned the Republican Party into the antithesis of the one he led in 2012 as its presidential nominee: alienating allies, degrading immigrants and splitting the nation with hatred. Now, Trump threatens to use an “emergency” declaration to circumvent Congress and start a trade war with Mexico.

And so Romney, now a senator from Utah, finally swung into action: He went to the Senate floor on Tuesday and … delivered a politely worded speech.

What? You thought he was actually going to do something?

This isn’t to pick on Romney; at least he speaks up. His 20-minute speech was a thorough rebuke of Trump, even if he took pains not to mention Trump by name: Romney spoke of the authoritarian menace of Russia and of North Korea, the benefits of immigration, the dangers of debt and the importance of allies when taking on China — all positions at odds with Trump’s actions. Romney assigned particular responsibility to the president in the need “to shut out the voices of hate and fear, to ignore the divisive and alarming conspiracies and to be more respectful, more empathetic to our fellow Americans.”

Amen. But if such jawboning is all Republican lawmakers can do to rein in the president, the cause is hopeless. Trump is plainly abusing his presidential powers, using “emergency” authority to ignore Congress so he can build a border wall, arm the Saudis and, now, slap tariffs on goods imported from Mexico. Republicans routinely grumble and sometimes threaten action but ultimately do nothing to stop him.

Maybe, just maybe, this is about to change. Republican senators on Tuesday declared publicly — and told White House officials privately at a lunch meeting — that they have the votes to reject Trump’s threatened tariffs against Mexico and to override a veto. It would be a meaningful rebuke of the president and his capricious governing style — but only if Republican lawmakers could finally overcome their habit of cowering.

Trump, asked about the incipient rebellion at a news conference in London with British Prime Minister Theresa May, left himself little room for a climbdown, saying Republicans would be “foolish” to block his tariffs against Mexico, given his strength among Republican voters. “I have a 90 percent — 94 percent approval rating as of this morning in the Republican Party. That’s an all-time record. Can you believe that?” he said to May, who is resigning because she lacks support within her Conservative Party. “I love records.”

As The Washington Post’s Philip Bump pointed out, no such poll seems to exist, and that figure wouldn’t be a record, anyway. (That was in keeping with Trump’s performance generally in the land of Orwell: He claimed that thousands of Britons were “cheering” for him rather than protesting.)

But Trump was animated in demanding that Mexico “stop this onslaught, this invasion” and prove that it isn’t “run by the cartels and the drug lords.” Trump predicted that the tariffs “will take effect next week” and called it likely that talks will occur “during the time that the tariffs are on.”

Given his supporters’ passion about illegal border crossings, it will be difficult for Trump to find a face-saving way to retreat from his threatened tariffs: He can’t capitulate to lawmakers without also appearing to capitulate to Mexico — and a continued flood of immigrants.

Back in Washington, some Republicans were already seeking a way out for Trump. House Minority Leader Kevin McCarthy of California cheerfully predicted a “solution that solves all problems” with Mexico, and he sided with Trump on his constitutional power to impose tariffs and sell arms under emergency decrees. “The president has the authority to do it,” McCarthy told reporters, an hour after Trump warned Republican lawmakers not to be foolish.

Romney, at least, was true to his principles. He told Bloomberg’s Sahil Kapur that “tariffs on Mexico are a bad idea all the way around.” And he broadened his critique of Trump on the floor. As Trump chastised NATO allies and endorsed a split in the European Union, Romney said: “We should strengthen our alliances, not dismiss or begrudge them.” As Trump, in London, stoked feuds with critics and trading partners, Romney said: “When it comes to cooling the rhetoric and encouraging unity, there’s no more powerful medium than the bully pulpit of the president.”

Well said. But if Romney and other Republicans really care about the president’s abuses, they’ll do more than grouse and grumble this time.

Dana Milbank is a columnist for The Washington Post. Follow him on Twitter: @Milbank.