Sadly, all three support the border fence, which I hate.
However, in Vanity Fair there's this:
McCain had been asked how debate over the immigration bill was playing politically. "In the short term, it probably galvanizes our base," he said. "In the long term, if you alienate the Hispanics, you'll pay a heavy price." Then he added, unable to help himself, "By the way, I think the fence is least effective. But I'll build the goddamned fence if they want it."