Between the 18 million people who voted for Hillary Clinton in the primaries and the many others who supported her candidacy but didn't cast a ballot for her, it is safe to say that John McCain will win the votes of literally millions of Hillary Clinton supporters in the November election. Almost all of these people will have well-considered and perfectly rational reasons for voting for McCain. Perhaps they don't think that Obama has the experience to be President. Perhaps they tended to side more with John McCain on the issues to begin with, but voted for Clinton because they liked her personally. An exceptionally large cross-section of the American public liked either Hillary Clinton or Barack Obama. Although there is a heavy degree of overlap between the two constituencies, there is a lot of room at the margins.
McCain, however, appears to be less interested in speaking to the millions of Clinton voters who fall somewhere between the cracks, and more interested in engaging the handful of crazies who dislike Barack Obama for wholly irrational reasons. Take Will Bower, the founder of a group called PUMA ("Party Unity My Ass"). On Saturday, Bower met with John McCain. On Wednesday, Bower attended Larry Sinclair's press conference, saw Sinclair literally accuse Obama of murder, saw Sinclair's lawyer wearing a kilt, saw Sinclair flee the room after the press conference because he was moments away from being arrested, and came away saying that Sinclair's story was "worth exploring". That means that McCain is either one or two degrees removed from the lunatic fringe, depending on what you think of Bower's state of mind.
Another of the people McCain met with, Paula Abeles, has a history of unethical and arguably racist behavior. Another was Harriet Christian, who gained her 15 minutes of notoriety by referring to Barack Obama as an "inadequate black man". Another is an author for the blog/conspiracist site No Quarter, which within the past week has accused of Obama of behavior ranging from having a liaison with Sinclair to promoting pedophilia through his Kids for Obama website.
There is too much risk to McCain that one of these people will become even more unhinged, and do or say something that gives him guilt by association problems. This really isn't that far removed from meeting with the "9/11 trUthers for Johnny MAC!" Facebook group. And to what benefit? So that you can be accused of pandering by Michelle Malkin? News flash: these people are not swing voters. Will Bower founded a group named Party Unity My Ass. He is not going to vote for Barack Obama. Paul Abeles is probably a racist. She is not going to vote for Barack Obama. Harriet Christian's vote is in the bag, Senator McCain. You do not need to win her over.
So what can McCain do to speak to the overwhelming majority of former Clinton supporters who are not batshit crazy? I think the communication has to be more implicit -- in fact, almost subliminal. The McCain campaign has actually been close to doing this a couple of times, although the execution in both cases was clumsy. The first time was during McCain's "green background" speech on June 3rd when he repeatedly used the phrase "That's not change you can believe in!", which explicitly echoed a phrase used by Hillary Clinton during the Texas Primary debate (Clinton's coda, "That's change you can Xerox", was not received well by the audience). The second was yesterday, when the McCain campaign accused the Obama campaign of "frat house" behavior for insisting that they be allowed to join McCain conference calls -- though the reference seemed out-of-context here, the phrasing was very Wolfsonesque.
As I said, these are ineffective examples of what might be an effective strategy for McCain. But the point is that Clinton spent 18 months fighting Barack Obama for the nomination, and there are a lot of lessons that can be drawn from that. Some subset of those things her campaign did and said that were effective back then are probably also going to be among the most effective ways now to dog-whistle to her supporters.