Why Are McCain Supporters So Angry?

Here's some footage from yesterday's McCain-Palin event in Waukesha, Wisconsin (it's the one our Ana Marie Cox called the angriest rally ever). The Washington Post described it this way:

There were shouts of "Nobama" and "Socialist" at the mention of the Democratic presidential nominee. There were boos, middle fingers turned up and thumbs turned down as a media caravan moved through the crowd Thursday for a midday town hall gathering featuring John McCain and Sarah Palin.