Poor Mitt Romney. He just can’t catch a break. With Romney preparing to lay into Rick Perry tonight over the latter’s claim that Social Security is a “Ponzi scheme,” here comes Rush Limbaugh to warn Romney that he does this at his own political peril. Seriously:

During his Monday show, Limbaugh warned the 2012 Republican field not to use Perry’s remarks against him. He specifically named Minnesota Rep. Michele Bachmann and former Massachusetts Gov. Mitt Romney.

“I’ve not endorsed anybody and this is not an endorsement” Limbaugh said. “But be very careful if you start attacking Rick Perry on Social Security and the ‘Ponzi scheme.’ There are too many of you out there who have already said that yourselves — Mitt Romney. Mitt, you have already called it a Ponzi scheme. And worse.”

“I’ve got a whole list of people here — media and outside — in politics who have referred to Social Security as a Ponzi scheme,” Limbaugh went on. “And ... I would like to warn everybody: Be careful here because you’re pandering to the media.”

See? Limbaugh has done the research — he’s stockpiled a whole list of Republicans who have already called Social Security a “Ponzi scheme,” too. This is a commonly held position, apparently. And if Romney protests Perry’s use of the phrase — as he has in the past — Limbaugh will point out that he’s helping the media damage the overall GOP cause. Or something.

This underscores something interesting about Romney’s challenge. He needs to argue that Perry’s overwrought and extreme positions and statements render him unelectable in a general election — while avoiding alienating voters and influential commentators who want this sort of combustible rhetoric, and don’t want their candidates to go all weak-kneed when the liberal media elite tells them they’re out of line.

What does it say that one of the most influential voices among GOP primary voters is putting the candidates on notice by warning them that it’s politically risky to protest the claim that Social Security is a criminal enterprise?