Prospects for an immigration overhaul are fizzling this year and some Democratic lawmakers are focusing blame on the pugnacious Democratic operative who works just down the hall from President Obama.

Rahm Emanuel, White House chief of staff and longtime party strategist, has argued privately that it's a bad time for Democrats to push an immigration bill, a potential landmine in the midst of a crucial mid-term election.

Emanuel's stance, coupled with his long-held wariness about the politics of immigration, is emboldening key Democrats to come forward and ask that he step aside from the issue.

"There's always a sense that no matter how hard we work, to get through the White House, we have to get through Rahm,'' said U.S. Rep. Raul Grijalva. "I would like immigration not to be part of the chief of staff's portfolio. It would make our ability to convince and access decision-makers in the White House a lot easier.''

Emanuel has a complicated history with the immigration question, dating back to the 1990s. As a top aide to former President Bill Clinton, he stressed the message that Clinton was hardnosed about policing illegal immigration.