To Bill Clinton, Gary Hart and Eliot Spitzer, you can add John Edwards, who made his family and “happy” marriage the centerpiece of his campaign while he carried on an affair.

What’s their problem?

Sure, Blagojevich plowed ahead with his scheming for months after learning he was under investigation. But that behavior isn’t so bizarre for a high-level politician.

In a survey of psychology experts, the Seattle Times found that politics tends to attract risk takers. After all, what kind of person wants a job where your job security is at the whim of voters? More often than not, just running for office is a huge professional risk…

In fact, many pols justify their misbehavior because they believe that the public needs their leadership so badly that they must do whatever it takes to preserve their power, no matter how unethical.