Three of the four leaders of the moderate Democratic Blue Dog Coalition have announced that they will retire at the end of this year. The latest to leave is Rep. Heath Shuler (D-N.C.), who got a country butt-kicking when he ran against Pelosi for House Democratic leader after the last election.

The argument, made by several sources who called POLITICO without solicitation, goes like this: Even if a moderate can withstand a bad lot in redistricting, raise millions of dollars and overcome ads warning of a second Pelosi speakership, his voice will be ignored in the next Congress.

“What I think is really lost here is a lot of the retirements were preordained the minute Nancy Pelosi decided to run again for speaker,” one retiring centrist said in an interview last week.

But Pelosi allies say the Blue Dogs are barking up the wrong tree, laying blame where it doesn’t belong. The San Francisco Democrat has ducked controversy this year, raised about $25 million for the party and done more to coordinate with the moderates in her caucus. Moreover, they contend, President Barack Obama will be the focus of Republican attacks, not Pelosi.

It all leads to a hotly debated question in Democratic circles: Is Pelosi more an asset or a liability?