It goes back to there’s a lot of ill will towards Senator Hagel because when he was a Republican, he attacked President Bush mercilessly and said he was the worst President since Herbert Hoover and said the surge was the worst blunder since the Vietnam War, which was nonsense. He was anti-his own party and people — people don’t forget that.
http://thinkprogress.org/security/2013/02/14/1598341/mcain-hagel-iraq/
McCain translated:
I'm a bitter old coot who's willing to piss on a fellow veteran for the sake of a draft dodger who lied us into war.
http://www.dailykos.com/story/2013/02/15/1187349/-John-McCain-s-very-very-reasonable-explanation-for-why-Republicans-filibustered-Chuck-Hagel