That quote about plastering on the make-up is extraordinary - it really does, on its own, suggest more than just loose screw. Googling it is a bit strange. It arises from a book called The Real McCain by someone named Cliff Schecter. This book, and especially the comment, is almost non-existent in mainstream media book reviews or news, while being very widely quoted in left wing blogs. It's not on snopes.

The only mainstream review I found was in the Guardian, which says this:

"The list of worrying incidents is long. In 1995 he ended up almost physically scuffling with aged Senator Strom Thurmond on the Senate floor. And, according to some accounts, in 2006 he had a fight with Arizona congressman Rick Renzi, throwing blows in a scrap whose details have only recently been detailed in Schecter's book. Schecter unearthed another unpleasant incident from 1992 in which McCain, tired after a long day's campaign, reacted badly to his wife Cindy teasing him about his baldness. 'At least I don't plaster on the make-up like a trollop, you cunt,' McCain snapped in front of eyewitnesses. Schecter says he has three sources for the story. McCain's campaign have denied it."

http://www.guardian.co.uk/world/2008/jun/22/johnmccain.uselections2008

Not sure what to make of it.

(Not sure wht his punches would look like given that he can't raise his arms.)