President Trump at the White House in Washington on Nov. 3. (Jabin Botsford/The Washington Post)
Opinion writer

President Trump is vexed by an ongoing Russia probe that is producing criminal indictments and at least one plea bargain. His signature issue, repealing Obamacare, failed. His shuffle of White House staff, a plethora of scandals (even apart from Russia), a slew of inexpert advisers and unfilled jobs, his compulsive lying, his attacks on democratic institutions, and his efforts to whip up racial and ethnic animus are unique in American presidential history. The voters have noticed all this, the latest Post-ABC News poll suggests:

Trump has an approval rating demonstrably lower than any previous chief executive at this point in his presidency over seven decades of polling. Fewer than 4 in 10 Americans — 37 percent — say they approve of the way he is handling his job. … The president’s disapproval rating has reached 59 percent, with 50 percent saying they strongly disapprove of the job he is doing. While little changed since the summer, both represent the worst marks of his presidency. …

Meanwhile, 65 percent say he has accomplished “not much” or “little or nothing.” This is up from 56 percent last spring. Forty-three percent of all Americans give him the lowest possible rating, saying he has accomplished “little or nothing.”

He is regarded by overwhelming margins as dishonest, lacking an understanding of “people like you” and bad at making deals. He is underwater in approval on issues including race relations, health care, the economy and world leadership.

His months of stoking the base have alienated the rest of the country. Few Republicans have abandoned him, but there is evidence there are fewer self-defined Republicans. Apparently,  he has not just put off a majority of the country but chased people out of the GOP.

The vast majority of elected Republicans seem intent on tying themselves to his mast, even as his presidency sinks below the water line. Their willingness to enable and endure his policy reversals and abominations and his grossly unacceptable behavior strike us as immoral as it is unnecessary. “The Post-ABC News poll asked self-identified Republicans and independents who lean toward the GOP whether they believed their party leaders should speak out when they disagree with the president. Overall, 71 percent said they should, with just 27 percent saying those leaders should avoid criticizing him, including 65 percent of Trump voters who say Republicans should air their disagreements.” They could actually push back and perhaps arrest their own polling death spiral.

However, Sens. Bob Corker (R-Tenn.), Jeff Flake (R-Ariz.) and just a handful of others are willing to take on the president. Corker, it appears, repeatedly gave Trump the benefit of the doubt, but as The Post reports,  came to “the growing realization that what concerned him about Trump was not getting better.” And who can really take issue with that? Certainly the American people have reached the same conclusions Corker has. Trump’s incompetence, erratic behavior, sabotaging of advisers, lying, refusal to learn the basics of his job and race-baiting have become more pronounced with time as the pressures and demands of the presidency grow.

The reaction of fellow Republicans to Corker in many cases comes down to “stop talking about it.” They don’t disagree with Corker; they merely don’t want to be reminded of their intellectual dishonesty and moral vacuity. It must grate on their nerves to hear Corker articulate what they know to be true but have not the nerve to say. They’d prefer Corker shut up rather than force any confrontation with a president who has utterly cowed them. They don’t want to be reminded that they’ve enabled an unfit president and have repeatedly placed partisan concerns and petty objectives over defense of the country and the rule of law.

Republicans who could challenge Trump’s behavior and thwart his dangerous schemes by and large are afraid of the base and are self-deluded in thinking they can extract some policy crumbs from the decaying presidency. Repeal the estate tax! Create a 25 percent pass-through rate! Really — that is worth endangering our country and damaging our democracy, worth pitting Americans against each other and degrading our politics?

Between Trump’s mendacity and GOP lawmakers’ passivity, the GOP of Abraham Lincoln, Teddy Roosevelt, Dwight Eisenhower, Ronald Reagan and both Bushes is no longer recognizable. It likely isn’t even rescuable. And if not, well, good riddance.