President Trump’s endorsement of Alabama Republican Senate candidate Roy Moore got us thinking about the game of chess. A recent Wall Street Journal article described how a bright amateur taught himself chess so he could play the world’s number one player, Magnus Carlsen. The rookie got wiped out.

On Wednesday Senate Democrats adroitly placed the Republicans, and Mr. Trump, in check. Six female Democratic Senators—Kirsten Gillibrand, Kamala Harris, Claire McCaskill, Patty Murray, Mazie Hirono and Maggie Hassan—called on fellow Democrat Senator Al Franken to resign over multiplying allegations of sexual harassment. Minority Leader Chuck Schumer said the same hours later. Mr. Franken’s office said he will make an announcement Thursday.

It is not hard to see what is going on here. The Democrats are creating a Frankenmoore nightmare for Donald Trump. Monday brought Mr. Trump’s Moore endorsement, followed by a commitment of support from the Republican National Committee. The next day, Rep. John Conyers stepped down from his House seat, clearly under pressure from fellow Democrats.

This is what the state of play looks like: The Democrats are eliminating their stains, while the Republicans are endorsing theirs. You have to believe in magic to think this is going to end well for Republicans.

In Wednesday’s Washington Post, Democratic operative Joshua Karp described the Moore strategy explicitly: “Whether he wins or loses, Republicans own him, and we are going to make sure the public knows that for the next year.”