Will Elizabeth Warren Endorse a Candidate? She Has a Few Options

“Progressives are going to want her to back the progressive,” said Rebecca Kirszner Katz, a veteran Democratic strategist. “This is a movement she has always been part of. They will want her to continue to be a leader in that movement.”

Yet a central part of Mr. Biden’s pitch is that he could defeat President Trump and help Democrats running in tough down-ballot races, with an eye on reclaiming the Senate. That plan faces many hurdles — but if it worked, an endorsement of Mr. Biden now could make Ms. Warren an enormously influential figure in Washington down the road, with real political capital on hand.

“Elizabeth Warren is a very logical progressive,” Ms. Katz said. “She’s always wanted to get her policies enacted. My guess is, she’s looking at all the numbers right now and seeing the best way to get her goals accomplished.”

If Ms. Warren sees both Mr. Biden and Mr. Sanders as deeply flawed, she could sit out the primary and promise to strongly support the eventual Democratic nominee. That decision could set Ms. Warren up to be a unifying figure later — but it could also be seen as a rebuke to Mr. Sanders. Still, neutrality is the route a number of other prominent former presidential candidates have taken so far, including Senators Kamala Harris and Cory Booker.

“She doesn’t owe anyone anything,” Ms. Morales Rocketto said. “She should take her sweet time.”

President Barack Obama had Organizing for America. Mr. Sanders has Our Revolution. Does Ms. Warren create a political organization that wades into campaigns or policy battles, keeping her brand prominent in the process?

In Iowa especially, the Warren campaign was famous for its extensive, creative political organizing efforts — does her team tap that knowledge to advance causes or candidates she cares about?

Ms. Warren is younger than Mr. Biden, 77, and Mr. Sanders, 78. She has national name recognition now. And politicians often run for president multiple times — this is Mr. Biden’s third bid, and Mr. Sanders’s second.