There’s a macabre parlor game obsessing many Democrats. Because they assume that President Trump will be unconstrained by law, ethics, tradition and precedent in trying to preserve the Republican majorities in Congress, they’re asking what’s the worst he can do to fix this year’s midterm elections. No idea, no matter how far-fetched, is off limits.

The tepid response to President Trump’s address this month about election vulnerabilities showed that he’s had only mixed success in his campaign so far. He’s failed to persuade the Senate to pass the SAVE America Act, which would impose onerous new rules for proof of citizenship on voters, and a federal judge has put on hold his directive to the Postal Service to limit delivery of mail-in ballots in states that refuse to share voter data with the federal government.

But the very fact that Mr. Trump decided to give a high-profile speech underlined his obsessive interest in the subject. And he continues to use the many other tools at his disposal to further this aim, including threatening to withhold federal funding from states that refuse to follow his directives on voting and neutralizing the bipartisan agency devoted to helping administer fair elections.

What else could President Trump do?

That’s just about the only thing Representative Joe Morelle thinks about these days. Mr. Morelle has represented a district in upstate New York since 2018, and he serves as the ranking member on the House Administration Committee, which supervises federal elections and oversight of House officers and operates unofficially as a kind of nerd caucus for those members who aspire to mastery of the House’s arcane rules and traditions.

“The president simply can’t get over 2020, and he’s reliving it every day. I feel like it’s the girlfriend in high school that got away,” Mr. Morelle told me. “Instead of accepting the fact that he lost an election — God forbid, which almost everybody does if you’re in this business long enough — he just attacks the system.” Mr. Morelle has been traveling the country — Los Angeles, San Francisco, Dallas, with more on the horizon — holding hearings about the risks to the vote, in particular for this year’s midterms.

While most of the attention so far has focused on who gets to register and vote, Mr. Morelle has also been noodling about what happens after the votes are cast on Nov. 3.