The Washington Post busts McCain on his claims about past presidential meetings with foreign enemies. His misunderstanding of the Reagan-Gorby meeting is particularly bad.
That said, I think China and the USSR--giant nuclear-armed powers--are a somewhat different deal than a rogue state like Iran. Iran has no comparable base of foreign allies and this seems like a case where isolation and ostracism--at the presidential level, which is different from less public forms of diplomacy--could make more sense. That question is admittedly a bit out of my element--though I'm still guessing, until I see contrary evidence, that it's what most Americans believe.
P.S. See Isaac and Matt for good--and possibly better! I'm still muddling through--thoughts on this topic. I do think however this may be a case where substance and politics clash (although that's also what I said about the gas tax holiday).