In my view, this is the perfect way to go after McCain. It goes after his integrity based on the fact that lobbyists run his campaign. It ends with the tie to Bush.
If Obama wants to win this campaign, I believe that his message needs to follow this theme:
The other thing we need to do is debunk the myth of the "straight talk express". I think those two messages - alone - will beat John McCain. This will swing the undecided vote towards Obama.