It is by far the greatest danger to First Amendment freedoms in American history: the modern “campaign finance reform” movement.
Every claim used to promote government controls over political campaign ads is untrue.
Here is a Reason.com article about Wisconsin political police–who raid people’s homes under cover of darkness and regularly tell those under investigation that they are not to tell anyone of the investigation.
This type of “gag order” policing was well-known in the Soviet era, and was a major component of the USA Patriot Act enacted in 2001.