The charge that the president is too tainted to exercise such constitutional powers as nominations to the Supreme Court doesn’t really jibe with the attitude that it’s too soon to consider impeachment. As Kevin Mack, the lead strategist for Democratic billionaire Tom Steyer’s Need to Impeach group, told me Wednesday, “If you’re not willing to say that Donald Trump should be impeached,” then “you don’t really have a lot of ground to stand on” in saying his Supreme Court pick is illegitimate or merits indefinite postponement.

“Members of Congress keep moving the goal posts,” Mack said.

I understand why they do, and it’s an uncomfortable position for them to be in. They don’t want to pursue—or mention!—impeachment until they’re sure it has a chance to succeed. That means a majority in the House and two-thirds of the Senate. That means Democratic control of the House after the midterms and about one-third of Republicans on board in the Senate. And that means Trump’s approval rating among Republicans falling underwater. There’s no sign that will ever happen, and so Democrats are stuck in this position of continually watching the evidence pile up and having nowhere to go.