While Mr. McCain, who is being treated for brain cancer and has spoken bitingly of Mr. Trump in recent weeks, glowingly praised his home-state colleague for his “integrity and honor and decency,” he did not use the Senate floor to second Mr. Flake’s worrisome message of a government and nation at risk. Mr. Flake is popular with his colleagues, and his fellow Republicans quickly noted how sorry they were to hear of his decision. But none joined him publicly in urging Republicans to stand up more defiantly to the president.
Senator Mitch McConnell, Republican of Kentucky and the majority leader, credited Mr. Flake as a “team player” and man of high principle after Mr. Flake’s speech. But Mr. McConnell quickly turned the Senate floor back to a minor debate over a budget point of order.
It was a jarring transition in a day of political shocks.
In a stunning one-two assault, Mr. Corker of Tennessee, the chairman of the Foreign Relations Committee, and Mr. Flake took on the president in terms rarely, if ever, heard from members of a sitting president’s party.
Mr. Corker, who has been feuding with the man he once contemplated serving as vice president, accused Mr. Trump of serial lying and debasing the office.
Mr. Flake, who has been a persistent Trump foe since 2016, never mentioned Mr. Trump by name in his remarks. But there was no doubt who he was talking about when he pointed to the “indecency of our discourse” and the “coarseness of our leadership,” and suggested his beloved Republican Party was being complicit in an “alarming and dangerous state of affairs.”
“We must never regard as normal the regular and casual undermining of our democratic norms and ideals, we must never meekly accept the daily sundering of our country,” Mr. Flake said.
But Mr. Corker, Mr. Flake and Mr. McCain remain the outliers. Mr. Corker’s exceedingly harsh assessment of Mr. Trump — delivered in a series of morning TV interviews in a reasonable, studied tone — and Mr. Flake’s announcement and damning speech bookended what was to be the initial centerpiece of a day on Capitol Hill intended to get lawmakers and the president on the same page with a difficult tax debate looming.
Mr. McConnell left his lunch with Mr. Trump and members of the caucus to emphasize the issues that bind congressional Republicans to Mr. Trump and play down the divisions underscored by Mr. Flake and Mr. Corker.
“There’s a lot of noise out there,” said Mr. McConnell, who made clear what the interests of the party are. “Tax reform is what we are about.”
Credit Al Drago for The New York Times
That statement defined the reluctance of other congressional Republicans to challenge Mr. Trump too directly. They have been willing to look past some actions and pronouncements by Mr. Trump that they consider beneath a president in hopes of pushing into law some of their long-sought goals, the most important of which are tax cuts. And with no substantial legislative achievements so far, the party is all in on a tax overhaul, recognizing that failure to deliver one will be a political disaster. That necessity ties them tightly to Mr. Trump, at least for now.
To be sure, there are Republicans in both the Senate and the House who are fully committed to the president and reject the views expressed by Mr. Flake or Mr. Bush, who recently expressed remorse about political “discourse degraded by casual cruelty” — an obvious reference to the Trump era in Washington.
But many others see Mr. Trump more as a means to an end, a way to enact their agenda since the president, as Mr. McConnell is fond of saying, is the only American who can sign a bill into law.
Mr. Flake’s remarks were a warning against that kind of thinking, the idea that some accomplishments — if they ever come — could compensate for the continuing upheaval and discord emanating from Washington and somehow reset the nation’s course.
“With respect and humility,” he said, “I must say that we have fooled ourselves for long enough that a pivot to governing is right around the corner, a return to civility and stability right behind it.”
Mr. Flake and Mr. Corker, along with Mr. Bush and Mr. McCain, represent significant cracks in the Republican wall of support and deference to the president despite widespread misgivings within the party. But they have nothing to lose politically. What is uncertain at this stage is whether Republicans with more at stake are going to join them in tearing down that wall.