A Primary Challenge to Obama? Unlikely.

Following Robert Gibbs's comments about the "professional left" earlier this week, The Hill's Sam Youngman follows up with some members of that class to ask whether they'd back a primary challenge to the president in 2012. The answer, in most cases: no. David Sirota and Markos Moulitsas both dismissed the idea; Firedoglake's Jane Hamsher sounded open to it.

And neither of the two most likely challengers to Obama, Congressman Dennis Kucinich and former Vermont Gov./DNC Chairman Howard Dean, have any plans to run in 2012:

Former Vermont Gov. Howard Dean and Rep. Dennis Kucinich (D-Ohio), a frequent presidential candidate, both said Thursday they had no plans to challenge Obama.

Gibbs invoked Kucinich's name in The Hill interview, saying some on the left wouldn't be satisfied if the prominent progressive who has called for a Department of Peace were in the Oval Office.

But Kucinich told ABC he had no plans to challenge Obama in 2012, and he pressed Democrats to concentrate on coming together.

Challenges to sitting presidents have been uncommon in recent elections, but they are hardly unheard of.

Read the full story from Sam Youngman at The Hill.