The measure could prevent programs like “24” and “Law & Order,” which used to star another GOP presidential hopeful, former Sen. Fred Thompson (Tenn.), from being aired before 10 p.m., according to the National Association of Broadcasters (NAB). The group is lobbying against the amendment.

“Broadcasters should not be allowed to use the public airwaves to disseminate violent or obscene material,” Brownback said in a statement. “The abundance of indecent material on television is one indication of the coarsening of our culture.”

Brownback’s amendment would allow the FCC to decide when violent programming should not be aired on broadcast networks, based on the likelihood that children might watch such shows. However, the NAB expects this would be between 10 p.m. and 6 a.m., since the FCC currently allows a “safe harbor” for indecent programming to air in that period.

The amendment, which would not affect cable or pay television, defines excessively violent programming as violence that is “patently offensive as measured by contemporary community standards.”

The NAB, however, says finding such a definition will be difficult.

“Are we talking about ‘Three Stooges’ violence? ‘Schindler’s List’ violence?” asked NAB’s Dennis Wharton.

Lawrence Tribe, a Harvard University constitutional law professor who is working with NAB on the issue, said the Brownback measure would likely be struck down on constitutional grounds if it became law. In a prepared statement, Tribe called the amendment “antithetical to the letter and the spirit of the Constitution.”