Attention public figures: Reporters aren't there to make you look good, or to make you look bad; they're out to discover the truth. The good ones, anyway.
If the truth is that you're potentially corrupt, it's best to offer no comment and walk away, and — I can't stress this enough — not go back after you think the camera's off and threaten to assault the reporter. I'm guessing Rep. Michael Grimm (R-N.Y.) thought reporter Michael Scotto violated some interview agreement that existed only in Grimm's head, but even that's no excuse for what transpired.
Bullying is horrible no matter who does it, but it's flat-out idiotic when a grown politician does it in front of a camera, as a response to feeling like he looked bad on camera. No matter what the ethical state of Grimm's finances, we now know for sure that he can't control his temper.
This is political behavior at its worst. And journalism at its best.