I know President Richardson was on the Oil Rig, but was he President when the bombs actually fell? I know the Enclave is the remnants of the government, but did anyone actually survive the attack from say, Congress and whatnot?
Richardson was, as many pointed out, definitely not alive yet when the Great War happened. As for the rest...
I'd have to say probably not, considering that government buildings would have been top priority targets for whoever bombed the DC area.
Furthermore, all the Radio Broadcast towers in Fallout 3, are they just automated distress calls? There are a few that have people talking, and one with a ghoul, but all the Lima November type ones have the same morse code signal I think.
Yeah, they're all automated. You can find the places that the broadcasts are coming from and turn them off, if you look hard enough.