Texas senator Ted Cruz, one of the most powerful Republicans in Congress, said the threat by Federal Communications Commission boss Brendan Carr to fine broadcasters or pull their licences over the content of their shows was dangerous.
"I got to say that's right out of Goodfellas," Cruz said, evoking the Martin Scorsese gangster movie.
"That's right out of a mafioso coming into a bar going, 'Nice bar you have here. It would be a shame if something happened to it'."
The senator's remarks are a rare example of a prominent member of President Donald Trump's own party publicly criticising the administration, highlighting deepening concerns over free-speech rights and Trump's threatened crackdowns.
Trump told reporters in the Oval Office on Friday that he disagreed with Cruz, calling Carr "an incredible American patriot with courage".
On Thursday, Trump had repeated an oft-stated contention that broadcasters critical of his administration perhaps should have their FCC-issued licences revoked.
Commenting further on Friday, Trump said, "I'm a very strong person for free speech," but added the broadcasters were so stacked against him he considered them to be an extension of the Democratic Party.
"See, I think that's really illegal, personally," Trump said of extensive criticism.
"That's no longer free speech ... That's just cheating, and they cheat."
Television network ABC, which is owned by Disney, suspended Jimmy Kimmel's late-night talk show after Carr threatened investigations and regulatory action against licensed broadcasters whothat aired Kimmel.
The owners of dozens of local TV stations affiliated with ABC said they would no longer carry the show.
The suspension followed Kimmel's opening monologue on Monday's show where he discussed the murder of right-wing activist Charlie Kirk, a friend and political ally of the president.
Conservative activists were angered by Kimmel's comments that they were using the assassination to score "political points" and his suggestion that the killer might also have been a conservative.
Prominent Democrats and civil rights groups condemned the Trump administration's pressure to punish Kimmel and others who speak negatively of the president.
Cruz, chair of the Senate's commerce oversight committee, joined the criticism on the Friday episode of his podcast, saying Carr's comments were "dangerous as hell".
Senate minority leader Chuck Schumer has called on Carr to resign or for Trump to fire him.
A defiant Carr said this week he was "not going anywhere" and vowed to continue his work taking on media firms and defending the "public interest".
Trump commended Kimmel's suspension while on a state visit to Britain this week, calling the Los Angeles comedian untalented and denouncing him for saying "a horrible thing about a great gentleman known as Charlie Kirk".
In Monday's monologue, Kimmel, who frequently lampoons Trump, mocked the president for turning a question about his grief for Kirk into a cheerful promotion for his planned White House ballroom.
"This is not how an adult grieves the murder of someone he called a friend," Kimmel said.
"This is how a four-year-old mourns a goldfish."
Kimmel has not commented publicly since his suspension, and the future of his show remains unclear.
Cruz said he had been mocked by Kimmel on air "so many times I cannot count", and he hated Kimmel's comments about Kirk.
However, "we shouldn't be threatening government power to force him off air".
"It might feel good right now to threaten Jimmy Kimmel, but when it is used to silence every conservative in America, we will regret it."
