Here’s why:
http://www.realclearpolitics.com/articles/2008/04/can_mccain_win_massachusetts.html
It’s a longshot but possible and possible enough to be worth it to campaign there.
And keep in mind that’s my best-case map - my worst case is a very narrow Obama win.
My worst case is an Obama win, narrow or landslide. The latter because the MSM manages to get a McCain explosion and a few Senior Moments, on video, and then play them over and over and over. Meanwhile virtually ignoring any such lapses on B. Hussein's part. 57 states for example.