McCain: GOP race is 'nastiest fight I've ever seen'

“Super-PACs have played a key role, unfortunately negative in my view, because they've driven up the unfavorables of all candidates and frankly made it more difficult to win an election in November," McCain said on NBC's "Meet the Press."

"This is the nastiest fight I've ever seen," he said of the GOP contest.

“It’s gone on too long, and its gotten way, way too personal.”

Click here to read more on The Hill's Ballot Box blog.