McCain can't use the internet, so he can't do the type of rapid survey of facts and reactions which is second nature to most people interested in politics. That may explain his tone deafness and msm-reliance on issues like ANWR, global warming, immigration and other 'maverick' (ie anti-conservative) stances. I can see how it might be a good thing to to have an internet illiterate President, but the implication that he's merely doddery and intellectually incurious won't win votes.
He needs Romney badly.