"The Democrats' favorite Republican"

I agree with Rich Lowry that putting an ad like this one on radio or TV would probably be quite effective. Sure, it's a negative ad, but it's neither malicious nor misleading. It's also not the sort of thing that would do great damage to Sen. McCain's chances in November, should he go on to win his party's nomination. Most importantly - at this stage in the race, at least - it would serve to remind Republican voters that Sen. McCain has parted ways with them on a whole host of key issues over the past several years. Like I said last week:

Some people say they're turned off by so-called negative campaigning, but as long as it involves drawing accurate distinctions between candidates, I don't find it objectionable. Mike Huckabee's record is more like that of a Southern Democrat than a Southern Republican, and Republican voters need to know that. Likewise, the press hails John McCain as a "maverick" for one simple reason - he has consistently sided with liberal Democrats on issues ranging from taxes to immigration to health care to global warming. Again, Republican voters need to hear these things. And not just from Rush Limbaugh.