Fact Check?

Mickey Kaus and Ramesh Ponuru (who is a McCain supporter) both say that Romney got the immigration position of McCain right in the contrast ad he's aired. Kaus says:
Santora [of the NY Times] has to be wrong. ... [pause for Googling] ... He is. Under McCain's bill, legal immigrants wouldn't collect Social Security "only after they are citizens." They would collect Social Security after they had become legal. In fact, legal immigrants apparently don't even have to become citizens now, under current law--if they're legalized, they can collect Social Security, even for work they performed here when they were illegal.

The distinction between "citizen" and "legal" is important, because it's easier to become a legal worker than it is to "wait" and become a full-fledged citizen. And McCain's "comprehensive immigration reform" would have legalized millions of current illegals fairly quickly. Hence, it would ... how to put it? ... "allow illegals to collect Social Security." Romney's charge seems basically accurate.
Ponuru adds:
I agree with Mickey Kaus that the media fact-checkers in this debate are distorting it more than the actual participants.