A good indicator of how bad it's gotten for the GOP is that a lifelong, dues-paying neocon like Ken Adelman decides to endorse Obama. This is the very guy who turned the infamous phrase that the invasion of Iraq would be a "cakewalk" -- in other words, did as much rhetorically to promote the Iraq war as anyone. As the saying goes, "If you've lost Adelman...."
On the other hand, I think that Powell's endorsement of Obama is much less of an event, and if anything simply demonstrates again how Powell is the very model of an "almost great" man. Had Powell decided to endorse Obama a month ago--immediately after the Palin interviews with Couric and Brown made clear what an absurd and irresponsible VP choice she is, but the polls were still very close--that would have shown some political courage, and would have made a more substantive difference to the campaign. But for him to do so now is simply unimpressive. Yes, he's coming down on the right side of what is frankly an obvious choice, but he's doing so only once there is no political risk to himself, only upside. If anything, Powell's decision to insert himself into the campaign at this particular juncture only fuels the racial ugliness which McCain has decided is his last worst hope to pull this thing out for himself.