Daron Westbrooke is a Ron Paul supporter. Sultan Knish has collected a series of his posts at a Ron Paul site. They show the pain that a true-believer in a candidate feels when his idol is shown to have clay feet. They also show how difficult it is to evaluate facts when you've committed to a person, heart and soul.
Mr. Westbrooke is not alone. It can be very hard to keep an open mind and to evaluate evidence fairly.
Addendum: I've been thinking about this since I posted it. One further point: Us moderns don't like to think we're prejudiced. But we are. If you have an emotional reaction to facts that contradict something you believe (Ron Paul is the best candidate, Bush was a draft dodger, Britney Spears is a good mother), it may be time to take a step back, take a few deep breaths and ask yourself why the reaction?
For me, the biggest part of being an adult is acknowledging and taking responsibility for errors. We do not like to admit that we make mistakes. But we all do, on a regular basis. Show me someone who doesn't make mistakes and I'll show you someone who is delusional. Admitting that you are in error is the first step to correcting the error and then to getting back in touch with reality.