It wasn’t with a heavy heart that Virginia Democratic Rep. Don Beyer on Tuesday endorsed initiating formal impeachment proceedings against President Donald Trump. And it was with unvoiced alarm that his fellow Virginia Democrat Rep. Abigail Spanberger ran from the impeachment question the same day.

Speaker Nancy Pelosi has a wicked impeachment dilemma, and Virginia captures it perfectly. It’s been one month since Congress got its hands on the Mueller report, and Mrs. Pelosi has spent that time scrambling to balance competing...