This is how it goes for election truthers. First the allegation was ballots marked with Sharpies, then voting machines tied to Venezuela, then more votes than voters. Now Mr. Trump apparently thinks his own Attorney General did an inside job. Electoral fraud does happen: A Pennsylvania man received five years of probation this spring after voting for Mr. Trump on behalf of his dead mother. The price of liberty, as they say, is vigilance. But the evidence doesn’t show anything real that could dent Pennsylvania’s 80,555-vote margin.

Even if it did, Mr. Trump would be two states short of victory. Georgia’s ballots were counted three times and a signature check done. The Arizona audit was a dud. A Michigan inquiry led by a GOP lawmaker ended up keelhauling “willful ignorance” and grifters who use misinformation “to raise money or publicity.” Mr. Trump’s lawyers who made baseless claims have been sued for defamation—twice. They’ve been sanctioned by a federal judge. Does Mr. Trump imagine a conspiracy so deep that practically everybody is in on it?

Mr. Trump is making these claims elsewhere, so we hardly did him a special favor by letting him respond to our editorial. We offer the same courtesy to others we criticize, even when they make allegations we think are false.