First, in a two-party system, there ought to be room for one party that doesn't reflexively accuse anyone who wants to discuss Social Security honestly of wanting to push Gran'ma off the cliff.
Second, this was a foolish tactic by Mitt, since whatever short-term advantage it gains him it reinforces his chief defect in the eyes of the base — and the reason his numbers are so soft: The suspicion that he's an opportunist with no coherent worldview. His attack on Perry for saying something little different to what he said last year has just added an entirely new topic to the old flipflopper critique, and an entirely new policy area on which, as with health care, Barack Obama will be able to say that he and his opponent are in basic agreement.
Third, the "granny card" is especially contemptible. I see even the Wall Street Journal worries that "the danger is that his rhetoric will scare the elderly." Why? Perry's said that those already receiving benefits and those within a few years of doing so will see no change. Still too "scary"? How about if he pledges that those in early middle-age will see no change? How about those in the final year of their half-decade Bachelor's Degree in Complacency Studies?
Throughout 2009/2010, while the media were running stories about how the Republican Party was leaderless and rudderless, the tea party guys and the town hall meetings moved the meter of public discourse in the direction of sanity. For 2011/2012, the GOP's heir presumptive is proposing to move it back to bipartisan somnolence. Not a good sign. The very minimum Republicans are entitled to in their candidate is a guy who gets the urgency.