Of course, there are some committee members who support Mr. Sanders. But they were a clear minority in the group we surveyed — only nine of the people we interviewed said Mr. Sanders should be the party nominee if he captures the most delegates but falls short of a majority.

One of them, Yasmine Taeb, a committee member from Virginia, argued that the party should be more concerned about a candidate like Michael Bloomberg, the former New York mayor.

“Why shouldn’t D.N.C. members — especially the ones of us who were elected by the grass roots — instead be concerned about a former Republican sexist billionaire who is trying to buy the election? I certainly am,” Ms. Taeb said. “I’m not concerned, however, with the progressive candidate with the largest grass-roots support across the country to win the nomination, because that’s precisely what is needed to defeat Donald Trump.”

Mr. Sanders and his advisers agree that his ideas will generate huge excitement among young and working-class voters, and lead to record turnout. (Such hopes have yet to be borne out in nominating contests so far, however.)

You may be wondering why I spent so much time interviewing these party officials. Winning the nomination is based on support from voters in primaries and caucuses, right?

Not necessarily.

Those contests proportionally award pledged delegates to candidates who reach 15 percent support in a state or congressional district. Under party rules, the candidate who captures a majority of the pledged delegates becomes the nominee.

But if no one hits the magic number of 1,991 pledged delegates, the contest goes to a second ballot at the party’s convention. That’s when the superdelegates could get involved. On that ballot, all 3,979 pledged delegates and 771 superdelegates would be free to vote for any candidate they chose.