Conservatives cycled through a number of candidates before landing, willingly or not, on Mitt Romney as their presumptive Republican presidential nominee. But as they enter the "acceptance" phase of the Romney nomination, there is at least one name that keeps making its way onto the could-have-been list: Sarah Palin. The former Alaska governor and 2008 vice presidential candidate has at least as much claim to be "next in line" as Romney, and her large, enthusiastic following would have both given her a leg up in the early polling and made her hard to attack, says Philip Klein in The Washington Examiner. Is Romney in fact "fortunate that he had to beat out Rick Santorum to claim the nomination rather than Sarah Palin"?

Palin could've won: You're nuts if you think Palin wouldn't have given Romney "a much tougher race than Team Sweater Vest," says Allahpundit in Hot Air. Her win wasn't assured, but Palin has the same appeal to blue-collar and evangelical voters that Santorum tapped so effectively, plus she also has charisma, a die-hard fan base, and Newt Gingrich–worthy anti-media credentials. If she had run and nailed the debates, Palin would have had a good shot at being the elusive "not Romney" dream candidate. 
"What if Palin had challenged Romney instead of Santorum?"

Oh, please. Palin would have imploded: We all know Palin would have bombed the debates, says Daniel Larison in The American Conservative. And this time her GOP rivals and conservative pundits would have ridiculed her mercilessly for "her ignorance of relevant policy matters." Romney wouldn't have had to lift a finger, and "Palin would have imploded last summer or fall as so many of the unqualified and demagogic candidates did."
"A Palin presidential bid would have imploded"

Let's not sell Santorum short: It all depends on which Palin showed up, says Ross Douthat in The New York Times. The "Palin who governed Alaska as an independent-minded populist" could have out-Santorumed Santorum by beating Romney on the blue-collar left and among most voters to Mitt's right. But the main weakness with this intriguing counterfactual is that the actual Santorum ran a great campaign and turned in solid debate performances. There's no reason to believe that the real Palin would have done either of those things.
"The Palin counterfactual"