Obama camp signals focus is solely on Romney

President Obama's campaign manager Jim Messina led a conference call with reporters Wednesday afternoon in which he harshly attacked Mitt Romney - and mostly declined opportunities to take shots at the other Republican candidates.

"Mitt Romney proved again last night that he will say and stand for anything to get elected, even if it means forgetting the positions he's previously taken," Messina said, referring to last night's Republican presidential debate.

Messina said Romney "tried to run away" from the health care law he signed as Massachusetts governor, is "taking hard-right positions" in immigration, and has "no credibility" on issues important to the middle class.

The Obama camp pointed specifically to comments Romney made to the Las Vegas Review-Journal on the housing crisis, where he said "don't try and stop the foreclosure process, let it run its course and hit the bottom" so that it can eventually "come back up."

Messina said that " Instead of offering a lifeline to responsible owners who were scammed," Romney "would leave them on their own."

The Obama camp also criticized a comment Romney made during the debate when Rick Perry criticized Romney for having employed a company to care for his lawn that hired illegal immigrants. A frustrated Romney said at one point, "I'm running for office, for Pete's sake, I can't have illegals."

Romney "didn't object to having undocumented workers working for him because it's illegal, he objected because it would hurt his political career," the Obama camp said. Messina argued that the "core principle that drives Mitt Romney [is] getting elected."

The call marks the latest instance of the Obama reelection team focusing on the former Massachusetts governor while largely ignoring his rivals. On CBS' "The Early Show" Wednesday morning, David Axelrod, Mr. Obama's chief re-election campaign strategist, called the "I can't have illegals" comment "the most unintentional revealing moment of the debate," deeming Romney a flip-flopper with "no core." That's a claim also being pushed in recent weeks by the Democratic National Committee.

On the conference call, Messina and campaign spokesman Ben LaBolt were asked to talk about the other Republican candidates. They mostly declined, with the exception of a relatively mild criticism of Perry's energy plan.

"It's certainly not up to us to judge the Republican ranks," said Messina.