People are not permitted to falsely yell "Fire!" in a crowded theater because it would cause a stampede and result in death or injury. O.K. I can follow that.
Congress has now made it illegal for advocacy groups to place ads w/in 60 days of an election which are supportive of a candidate or critical of a candidate. O.K. ...and the compelling reason for such a restriction on political speech is......stampede? no. Mayhem? no. Protection of incumbents? Bingo.
Yeah, I guess your right it's the same principal. /sarcasm
How about congress's right to establish rules regarding the elections of its members ?