John Harwood's NYT article today brings back a problem for McCain that was raised earlier: Ad man Mark McKinnon has said he won't work against Barack Obama.

Back in February, McKinnon explained his feelings to NPR:

"I would simply be uncomfortable being in a campaign that would be inevitably attacking Barack Obama," said McCain adviser Mark McKinnon in an interview with NPR's "All Things Considered." "I think it would be uncomfortable for me, and I think it would be bad for the McCain campaign." ...

"I met Barack Obama, I read his book, I like him a great deal," said McKinnon. "I disagree with him on very fundamental issues. But I think, as I said, I think it would a great race for the country."

So McKinnon doesn't want to attack a guy he respects, which is respectable in its own right. A McCain-Obama general might not be as personal as the primary has been, but it won't be any less hot. Things get ugly and you find yourself doing ugly things.

But that's also the business that McKinnon chose. And rather than resigning himself to the likelihood that things will get unredeemably ugly, perhaps McKinnon should remain and try as best he might to keep it clean and hard-fought. Because there's nothing wrong with playing to win in a contest between champions, which is what a presidential election is.