By dropping his reelection bid, President Biden is reversing more than a century of democratizing the choice of presidential nominees via primaries. That power now shifts back to party bosses from the people, as insiders can swap out any candidate who’s losing and call in a ringer.

“I believe,” Mr. Biden wrote in a letter to the nation on Sunday, “it is in the best interest of my party and the country for me to stand down.” It’s a nit worth picking that he put “party” before “country,” reversing President Hayes’s maxim, “He serves his party best who serves his country best.”