If I had to guess, I'd say it's an Electro-Voice Model 654.
Good call.
I know a little about mics and figured it for an ElectroVoice, but couldn't figure out the exact model.
One geeky thought - notice that the mic cord does not plug into the mic, but into the stand. This is very unusual. It's probably so that the mic can be swiveled around to whoever's talking without twisting the cable.
Another geeky thought - I wouldn't think that type of mic would be ideal for that setting. It's omnidirectional - it picks up sound from all directions. Perfect for placing in the middle of a multi-person discussion but less so for a Congressional hearing. I figured they'd use a mic with a much more directional pattern, like a shotgun mic, which would only pick up the speaker it's pointed at. This mic could get a lot of extraneous chatter from a packed room.
