The first Republican presidential primary doesn't take place for more than nine months, but an attack by former Sen. Rick Santorum (R-PA) on former Gov. Mitt Romney (R-MA) indicates that the race is well underway.


In a fundraising letter sent out Tuesday, Santorum suggested that Romney was better suited to be President Barack Obama's running mate.

"Mitt Romney has been spending the last week defending his failed 'experiment' in government-run health care -- and based on news reports it hasn't been working," Santorum wrote. "The same way that President Obama has been defending ObamaCare since its passage through Congress."

In a speech at the University of Michigan's Cardiovascular Center Thursday, Romney stood by his Massachusetts health care law that closely reflects the controversial plan Obama enacted last year.

"I respect the views of those who think that we took the wrong course," Romney said. "I also recognize that a lot of pundits around the nation are saying that I should just stand up and say, this whole thing was a mistake -- it was just a boneheaded idea and I should just admit it and walk away from it. I presume folks would think that would be good for me politically. But there's only one problem with that: it wouldn't be honest. I in fact did what I thought was right for the people of my state."

Santorum used the opportunity to ask supporters to kick in some cash for his campaign.

"I believe we need to limit the size of government and return to a time when elected officials did what they thought was right -- not create 'experiments' that drive up taxes and reduce the quality of life for our citizens," he said.

"I know most conservatives will agree with me. But my first challenge is to raise enough funds to get my message out to as many voters as possible."

A recent survey by the Quinnipiac University Polling Institute showed Romney leading the pack with 18 percent of Republican voters supporting him. Only one percent of GOP voters were interested in casting a ballot for Santorum.

-- With earlier reporting by Sahil Kapur

[h/t: Think Progress]