Republican Presidential Candidate Rick Santorum speaking at the Values Voter Summit in Washington, DC. Photo: Gage Skidmore.

Fox News – Rick Santorum, making his case for why he should stay in the uphill race against Mitt Romney, said Sunday that Republicans must not repeat the mistake of 2008 and prematurely nominate someone who can’t win in November.

Though Romney argues he’s by far the toughest competitor to go up against President Obama, Santorum compared Romney to Sen. John McCain in 2008.