Some undoubtedly would. But they’d be cowards. Their objective should be to render him as impotent as possible.

It is also true that Flake’s record is better than all but a handful of his Senate Republican colleagues. This week, he and Senator Chris Coons, a Democrat from Delaware, are planning to ask for a vote on legislation that protects the investigation of the special counsel, Robert Mueller.

But Flake didn’t write the original legislation. Other colleagues on the Senate Judiciary Committee did. And it would be shocking if it went anywhere.

The truth of the matter is this: If Flake believed, all along, that Trump posed a genuine threat to democracy — that he is the least stable element on the periodic table of American presidents, with a half-life of 22 minutes and a terrifying potential to blow things up — then why did he slavishly follow the president’s desires at all? Why did he ever allow ideological ends to justify republic-endangering means?

In my initial review, I did note that Flake’s words wouldn’t be worth much if they weren’t matched by deeds. But I made this point late, at the bottom of the staircase. (Thank goodness it appeared in the headline.) I was otherwise snowed by Flake’s candor. Along with lavender-scented baths, chamomile tea and barbiturates, books by politicians tend to rank among the world’s most potent soporifics. His was not. He wrote of the despair he was feeling beneath the lacquered smile.

But Flake, as a sitting senator, has been in the position to do more than despair. He has been in the position to swallow his misgivings about policy and align himself with the opposition. He could have waged guerrilla warfare against Trump’s agenda at decisive moments, as John McCain did by refusing to vote for the repeal of Obamacare. He could have voted against the 2017 tax bill, which should have been concerning to a deficit hawk anyhow. He could have stuck with his reservations about the Supreme Court confirmation of Brett Kavanaugh, credibly accused of sexual assault, rather than deciding the F.B.I.’s one-week investigation into the matter — an investigation he called for — was sufficient. (How thrilled I was he’d shown some spine! And then it collapsed in a heap, like so many mah-jongg tiles.)

If you’re a truly committed Never Trumper, there’s a fundamental problem with selectively supporting Trump’s agenda. Whenever you hand him a vote, you strengthen him. You contribute to his roster of accomplishments. The more victories he accumulates, the more reasons he has for voters to buy the same product in 2020.