It begins. President Obama heaped praise on Mitt Romney’s Massachusetts health care reform at a Boston fundraiser last night, which Byron York observes is just a “brief preview of what will come in the general election”:

“With a little assist from the former governor of Massachusetts, we said that health care should no longer be a privilege in this country,” Obama said.  “It should be affordable and available for every American.” A short time later, at a smaller fundraiser in a private home in Brookline, Obama said, “Our work isn’t done.  Yes, we passed health care, with an assist from a former Massachusetts governor.”  The crowd, which had paid $35,800 per couple to attend, broke into laughter and applause.  “Great idea,” Obama added.  “But we still have to implement it.”

Obama’s comments were aimed at disheartening the GOP and dampening enthusiasm for Romney, who was cited as leading the GOP field in the latest Rasmussen poll. Romney’s problem is that this is a tough attack to counter. It’s hard to go on the defensive against a compliment. And so far he’s been unable to sum up the difference between RomneyCare and Obamacare in a quick soundbite.

But every time Republicans hear this attack, they will grow more panicked about the prospects of Romney winning the nomination. If Romney wants any chance of succeeding, he needs to come up with a response that will placate conservatives, and he needs to do it soon.