As for that other side, the Democrats don’t have much leverage in all of this. But they do have three things going for them.

First, most of what the Republicans are hoping to do simply isn’t popular. Big tax cuts for the rich and even for major corporations, which are more justified substantively, aren’t popular. Enormous budget cuts aren’t popular. Replacing Obamacare with something resembling the health care bill the House passed, recent polling shows, would be horrendously unpopular.

Second, Mr. Trump is unpopular. It’s still too early for post-Comey fallout polls, but right now his approval rating is at just under 40 percent. He got 46 percent of the popular vote last November. That means he’s lost 13 percent of his voters. If he gets down to the mid-30s, he will have lost around a quarter of his own voters — who were, remember, a minority to begin with.

Numbers like that make doing big things difficult. Ronald Reagan was above 60 percent when he signed that tax bill in October 1986 (his rating quickly plummeted the next month, when the Iran-contra affair broke). When you’re at 60 percent and you tell America that your tax bill is great and should pass, that’s one thing. When you’re at 40 percent and half the country thinks it’s scandalous that you’re even still the president, that’s another.

Third, pay attention to these two coming special elections to fill vacant House seats. The first happens soon, on Thursday. It’s in Montana. It’s a very Republican district — in fact it’s the whole state, Montana’s population entitling it to just a single at-large representative. The Cook Political Report rates it Republican +11 — basically a default Republican seat.

But the Democrat, Rob Quist, is running competitively. Likewise in Georgia, a Democrat, Jon Ossoff is running strongly in a district that Cook rates Republican +8 (it’s Newt Gingrich’s old congressional district). Both candidates have taken strong pro-Obamacare stances. It’s probably a long shot that Democrats will win both races. But if they do, that will set the Richter scales to nine in Washington. Even one Democratic win would make House Republicans panic. And panic tends to produce more panic.

This is not the spring Paul Ryan and Mitch McConnell had planned. It was supposed to be the Republican version of Franklin Roosevelt’s first 100 days. Instead, it has been a disaster. And whatever their apologists will later say, it’s not entirely Donald Trump’s fault.