There seems to be a gowing phenomenon of disaffected Republicans joining the Obama camp. There are two types of Obama Republicans that are emerging in the wake of the inevidable nomination of John McCain.
The first group of Obama Republicans are the right-wing talk show crowd who can't stomach McCain's legislative resume. These are people who want to send the GOP out into the wilderness for 2-4 years so that it can do some soul searching. These people seem to be taking on Obama as their "lesser of evils" candidate. These people hate John McCain, but they despise the Clintons. I think they can even bring themselves to find something inspiring about Obama, despite the fact that he is slightly to the left of Hillary Clinton.
The second group of Obama Republicans are the people of the party who feel disenfranchised by GOP policy for the past 15 years. These are the "post-partisan" group, who aren't looking for ideological discipline, but rather pragmatic solutions to our problems. What these people see in Obama is what many Democrats see, a fresh face with new ideas.