“I haven’t heard of a credible name that has been floated that would challenge President Obama,” said David Sirota, a prominent liberal blogger. “I haven’t heard of that. I think it would be very difficult to do.”

Markos Moulitsas of Daily Kos, who is also a columnist for The Hill, said he didn’t think Obama would get a 2012 primary challenge “in a million years.” In an e-mail, Moulitsas also said Obama shouldn’t be challenged.

Still, some influential figures on the left, which erupted in fury this week at criticism White House press secretary Robert Gibbs made in an interview with The Hill, suggest a multitude of voices in New Hampshire and Iowa could be helpful to the party.