Dems, of course, could also pull themselves together and unite behind their nominee for 2020. But even allowing for how much they want to defeat Trump, it’s more likely their savage attacks on each other will get bloodier and cost them the election.
For one thing, there is no strong Trump-like personality capable of dominating the party and turning it to a more sensible policy course. And recall that Clinton and Bernie Sanders never reconciled before the 2016 general election and there is still bad blood between them.
As for LBJ, his cannibal line proved prophetic. Sen. Eugene McCarthy, running against the Vietnam War, nearly upset Johnson in the 1968 New Hampshire primary, and the president, realizing he had lost his party, shocked the nation by announcing he would not seek re-election. In the fall, Richard Nixon was elected president.