Yet on consequential issues, Mrs. Clinton isn’t giving much hint about whose side she’s on. She’s steadfastly refused to say whether she supports or opposes the Keystone XL pipeline proposal, maintaining it would be inappropriate for her to comment given that she worked on the issue at the State Department. At a town-hall event in New Hampshire last week, she told one person who asked about Keystone that she might not spell out her position until she becomes president.

She has also been guarded when it comes to a major 12-nation Pacific trade deal being negotiated that has split the Democratic Party.

One labor leader who listened to Mrs. Clinton make a pitch for the AFL-CIO’s endorsement at a closed-door session last week came away unimpressed. RoseAnn DeMoro, a member of the labor federation’s executive council, said Mrs. Clinton didn’t take a position on the trade deal, which many union leaders oppose.

“If I were to characterize her, she’s extremely cautious,” Ms. DeMoro said in an interview after Mrs. Clinton’s appearance. “It’s sad because as a woman, I think she’s unfairly judged. On the other hand, she’s become so cautious that I actually don’t know what she thinks. I don’t know what she believes. I know what she says, but I don’t know what she believes.”