Scott Galupo doubts that Romney can attack Perry from left (on entitlements) and right (on immigration) at the same time (via Allison):

But, at this point in the history of U.S politics, it would be a highly unusual creature who could launch both attacks simultaneously.

I would love to believe that Romney’s phony demagoguery will not do him any good, but why couldn’t Romney be successful in using both lines of attack against Perry? Perry’s record on immigration puts him much closer to George W. Bush and John McCain than it does to rank-and-file Republican voters. Perry has not been as visible or outspoken on the national level in support of mass immigration, but he is at odds with the vast majority of the party on this issue. There isn’t much public support for making changes to Social Security and Medicare. Even among those that Pew identifies as “staunch conservatives,” support for making such changes is just 47%. Positioning himself as the defender of entitlements and borders isn’t that strange of a combination. This is a fairly logical combination for someone running to be the nominee of a party with large blocs of elderly voters and opponents of liberalized immigration laws. It is certainly unimaginative, and no one is ever going to say Romney shows political courage, but that doesn’t mean that it can’t work. Besides, how better to describe Romney than as a “highly unusual creature”?