Instead he must decide what he will do with what he has built — starting with how he conducts his campaign over the next two months, how he navigates the party’s national convention in July, what role he plays in the general election and, perhaps most important, what happens after the November results have been tallied.

At the heart of many of these questions is another one: Will the self-described democratic socialist, who has run all his past campaigns as an independent, continue calling himself a Democrat after his presidential bid ends? (After this article was published online Wednesday, Sanders’s campaign manager said he expects the senator to be a member of the party “for life.”)

Sanders advisers insist that, with the candidate focused on carrying on his campaign through the last of the primaries in June and on to the Philadelphia convention, there have been few discussions about such questions. But his wife, Jane, offered a preview of the candidate’s thinking in an interview with The Washington Post just before New Yorkers went to the polls.

“If he’s president, he wants to keep this movement going,” she said. “If he’s not president, he’ll have to keep this movement going for a lot more reasons, because nobody else wants to accomplish what has ignited the interest of the voters.”