For a while there, it looked like President Joe Biden was maybe, just maybe, in the clear. On Monday morning, he gave a forceful defense of his candidacy in a call-in interview to MSNBC and in a letter to congressional Democrats.

Then came Wednesday, when the “elites,” as Biden has branded Democrats who want him to quit the presidential race, redoubled their efforts. First, the most senior House Democrat declined to endorse his candidacy. Then, Hollywood celebrity donors—including the biggest of them all, George Clooney—called on the president to quit the race, and a scheduled lunch for donors at next month’s Democratic National Convention was suddenly scrapped.

The drip, drip, drip came in a series of potentially devastating…