Jamie thinks the quotation from McCain below puts the Hamas issue to rest. I'm not so sure. In his response to Rubin, McCain says, "They're the government; sooner or later we are going to have to deal with them, one way or another." He doesn't precondition this upon Hamas's changing its behavior. The quotation Jamie cites has McCain saying hopefully Hamas will recognize Israel and renounce terror, in which case we could do business with them again. This doesn't address the question of exactly what we should do in the (likely, as it's turned out) event that Hamas fails to shape up. It seems to imply continued isolation; then again, his statement to Rubin implies a willingness to "deal with them," which could mean a lot of different things. Hence, my earlier remark that it would be nice if McCain could explain what he meant in the quotation Rubin cites--it must have meant something.
This whole exercise is admittedly fairly silly--presumably McCain would say that he's never been in favor negotiating with Hamas (which would put him in the same boat as Clinton and Obama). Since the only evidence to the contrary is open to interpretation, it would be reasonable to take him at his word. But for McCain to hammer Obama for his openness to diplomatic engagement with nefarious regimes, as though it's a facially absurd proposition he would never consider (someone should tell Robert Gates!) seems a bit opportunistic, given that just two years ago he apparently recognized it for the complicated question of statecraft it is.