It's pretty obvious to anyone John McCain has a bad temper. You've probably read many stories. If you've watched the debates you can see him struggling to hold it back, all the while being condenscending. Well here's a nice little video with even more evidence.
Or how bout when he was gambling in Puerto Rico?
Or when he call his wife a cunt?
Military leaders on McCain's temper
McCain's Top 10 Temper Filled Moments
Seriously... 43% want this man elected?