Another theory: She recognizes that she probably will not win the nomination. But a couple of possibilities are at play here. One is that lightning will strike, and she will become the nominee. Or, perhaps more plausibly though counter-intuitively, she is actually helping the party by staying in.

That’s because her message about disenfranchisement seems to have taken hold. As Ms. Williams noted, there are still 10 contests to go, with perhaps 43 millions votes to be counted. To short-circuit the process would anger her many of her supporters, especially those who have not yet voted. Thousands of people are coming to her rallies now, and her campaign has organized events in post-Pennsylvania states where people are thrilled to be part of a process from which they are normally excluded.