What's behind the shady false attacks on Cliff Stearns?

Cliff Stearns never struck me as controversial. Quiet and unassuming, he's managed to forge a solidly conservative path during his time in Congress, but largely avoided the spotlight until this past year, when he earned accolades for his work leading the Solyndra investigation. So I was, quite frankly, shocked that this election year brought not only a slew of primary challengers against Stearns, but also at the level of vitriol of their attacks on him.