McCain giving up on Colorado, now aiming for Pennsylvania - bold or desperate?

Tweet

Just heard that John McCain's new electoral strategy is to pull out of New Mexico, Iowa and now even Colorado and concentrate instead on winning the remaining swing states that Bush won back in 2004 and, to take him over the 270 EVs that he needs, try to get Pennsylvania that went for Gore and Kerry in the last two elections. I can understand McCain giving up on Iowa and New Mexico as these seem to be going heavily towards Obama. But Colorado seems to me easier for him to win than Pennsylvania! And if McCain loses Colorado as well as Iowa and New Mexico, then he must capture a Kerry state, ie Pennsylvania. But polling shows McCain upto 12 points down in that state. What do you think? Is this new McCain electoral strategy realistic or an act of sheer desperation?