More from the NYT on a brokered convention

"Jay Jacobs, the New York State Democratic Party chairman and a superdelegate, echoing many others interviewed, said that superdelegates should choose a nominee they believed had the best chance of defeating Mr. Trump if no candidate wins a majority of delegates during the primaries."

"A vast majority of those superdelegates — whose ranks include federal elected officials, former presidents and vice presidents and D.N.C. members — predicted that no candidate would clinch the nomination during the primaries, and that there would be a brokered convention fight in July to choose a nominee."

"In a reflection of the establishment’s wariness about Mr. Sanders, only nine of the 93 superdelegates interviewed said that Mr. Sanders should become the nominee purely on the basis of arriving at the convention with a plurality, if he was short of a majority."

"In recent days, both Mr. Biden and Senator Elizabeth Warren of Massachusetts said that Mr. Sanders should not become the nominee if he arrived at the convention short of a delegate majority."

"Representative Veronica Escobar of Texas said that if Mr. Sanders arrived at the convention with 40 percent of the delegates, it wouldn’t be enough to convince her to vote for him on the second ballot."

"The campaigns are already strategizing about how they will handle a protracted convention battle. Superdelegates, too, are brushing up on the rules: Ms. Pelosi invited House Democrats to a meeting at D.N.C. headquarters on Thursday to review the details of the convention process."