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Flailing presidential candidate Newt Gingrich says he's been talking with Mitt Romney and Rick Santorum about the best way to beat President Obama, but the non-Romney candidates aren't showing signs of dropping out.

Gingrich told a Milwaukee radio station today that "we have all three been talking with each other all during the process because we all three understand that the number-one mission is to defeat Barack Obama."

"So I talked to Santorum recently, and I think that's just a part of the process," Gingrich said.

Gingrich and Romney met last week in New Orleans, though the former House speaker has denied that the conversation was about making some sort of deal.

Romney has always been seen as the likeliest candidate to win the Republican nomination, even as Gingrich and Santorum alternately stole the show for brief periods during the primary season. Now Romney is as inevitable as ever, having coordinated formal endorsements with party bigs like George H.W. Bush, Marco Rubio and Paul Ryan.

"We are people that want to make sure the Republican Party candidate is capable of defeating a guy that we think would be a disaster to reelect, and I think you also see us focusing more and more attention on Obama," Gingrich said today.

Gingrich hasn't always stuck with what he's said during the primary campaign, notably his pledge to stray from negative attacks against the other candidates that he abandoned to tackle Romney.

Gingrich recently refocused his strategy on winning the nomination by preparing for a floor fight at the party's August convention in Tampa, assuming that Romney doesn't get enough delegates to lock up the process. Santorum similarly has vowed to contest the primary as long as he can.

Last night, Santorum mocked Romney in a speech to supporters in California, pointing to the former Massachusetts governor's positions on abortion.

"I was out there leading the charge while Governor Romney was contributing money out of his own checkbook to Planned Parenthood," he said. "Romney said after the Etch A Sketch flap that he's going to run as a conservative in the fall. I'm not going to run as a conservative. I am a conservative."

Santorum's campaign also prepared a research-based attack on Romney yesterday, charging that his former "green quarterback" in Massachusetts is Obama's "top air quality official," Gina McCarthy.