I've written a couple times now about the importance of Latino voters in this election, and future elections, and I've also noted that if the Republicans want to keep Latino voters from going permanently Democratic, then John McCain is probably the best candidate they could have chosen.

Even while his party's base became more strenuously anti-illegal immigration (and, in some cases, anti-immigration period in tone if not substance), McCain remained a moderate on the issue. He even co-sponsored what's been called "comprehensive immigration reform" -- the right called it "amnesty" -- with Ted Kennedy. But then he started running for president again, and he had to shift quickly to the right to mollify many in his party who aren't happy with him on several fronts.

Now, he's trapped: If he sticks with his previous position, he turns off his party's base and risks indifference leading to low turnout or even open revolt. But if he moves to mollify the base, he risks more Latino voters going to the Democrats. So his solution, apparently, is to take two positions and make his rhetoric fit the audience.

That, at least, was the news last week, after a meeting McCain held with Latino community leaders in Chicago. After the meeting, Rosanna Pulido, a Latina who runs the Illinois branch of the Minuteman Project, a controversial group that has set up some of its own border patrols, told reporters that McCain's language seemed tailored to the crowd, and that he'd spoken in support of comprehensive immigration reform. "He was telling one group of people one thing and the Hispanics another," Pulido said to ABC News' Jake Tapper. "I'm a conservative and I think he's throwing conservatives under the bus."

As the Obama campaign pointed out, at a debate earlier this year, McCain said that if it came up again in the Senate, he'd vote against the legislation he'd previously co-sponsored with Kennedy.

This is only one of McCain's recent flip-flops -- my friend Steve Benen has documented dozens -- but it's one that may be uniquely important both to his chances this fall and his party's chances in the years to come.