I wrote about the possibility of this on Friday, so read that post first if you haven’t yet. Long story short: It could work as long as Romney balances the attacks by insisting on entitlement reform.

But I have to say: Given the magnitude of the debt crisis, the thought of any Republican being hammered by another Republican for not loving entitlements enough makes me queasy.

Why should Romney attack Perry directly when the Democrats, the liberal media and Michele Bachmann will do it for him? Romney’s strategists note that Perry will have to survive five debates in six weeks — ample opportunity for Bachmann to “rip his eyes out” (as she did to Tim Pawlenty) or for Perry to blow himself up.

If Perry fails to implode and continues to surge in the polls, Romney eventually will have to go on the attack — an assault his advisers say will commence “at a time of our choosing.” Romney strategists are quick to note that in his book, “Fed Up!,” Perry writes that “By any measure, Social Security is a failure” and calls the program “something we have been forced to accept for more than 70 years now” that was created “at the expense of respect for the Constitution and limited government.”

Look at what happened to Paul Ryan when he proposed a plan to save Medicare, they say. Romney’s campaign will argue that Perry is against the very idea of Social Security and Medicare, and that he will use Perry’s book to scare seniors in early-primary states with large retiree populations, such as Florida and South Carolina.

He’s planning to hit him on other things too — immigration, career politician, cronyism, etc — but none of those would have the electric-shock effect of the primary turning into a referendum on who’ll do more to preserve Medicare as is. Two broader strategic points here. One: If Romney goes this route, he’ll be well positioned for the general election if he’s the nominee — but if Perry’s the nominee, this could weaken him significantly. The Democrats will play Mediscare games against either of them regardless, but if Romney beats them to the punch by using that accusation against Perry, it immunizes him from the charge to some extent once he faces Obama. The first time Debbie Wasserman-Schultz screams that Mitt wants to eliminate Social Security, he’s got a ready answer — not only doesn’t he want to do that, but he won his party’s nomination against a guy who (allegedly) did by calling him out on it. If Perry beats Romney for the nomination, though, then the DNC has a golden attack line handed to them: “Rick Perry is so radical on Medicare that he even scares other Republicans,” punctuated by a shot of Romney attacking Perry on those grounds at one of the debates. It would be devastating. Even if Perry tries to explain it away, the fact that he’d be on the defensive on this issue of all issues would be trouble.

The other strategic point: I’m really curious to see how the base would greet a Mediscare attack from Mitt Romney of all people. On the one hand, even tea partiers are reluctant to cut entitlements when asked about it in polls. On the other hand, conservatives are increasingly aware of the role entitlements play in driving the debt crisis, their pet issue. Will they back away from Perry once Romney raises suspicions about his support for the programs? Or will they turn on Romney, seeing his defense of the programs as further evidence of his big-government tendencies? Perry could, if he chose, attempt to counter Romney with the same attack House Republicans used against the Democrats last year — namely, that they’re the true protectors of Medicare because they opposed the gigantic new health-care law that’s going to end up siphoning off money from the program. Perry could use a variation of that argument to hit Romney on RomneyCare. But I’m not sure he’ll do it: Given a chance in Iowa on Saturday to walk back the tough talk in his book about entitlements, he doubled down by calling Social Security a Ponzi scheme for the young and a “monstrous lie on this generation,” and later added, “I haven’t backed off anything in my book.” Bold words. How will they play in, say, Florida?

As a sneak preview of what’s coming, here’s what Romney’s fans have already cooked up against Perry.