US Senator Ted Cruz has accused the head of America's broadcast regulator of acting like 'a mafioso' in the suspension of late-night host Jimmy Kimmel - the sharpest attack yet from a conservative Republican on the controversy.

He said Federal Communications Commission (FCC) chairman Brendan Carr's threat to ABC over their comedian's monologue about slain conservative influencer Charlie Kirk was 'dangerous as hell'.

'That's right out of Goodfellas,' the Texas Republican said, as he affected a mobster's accent.

Other Republicans in Congress have been more muted in their criticism of how the FCC pressed Disney-owned ABC to take action on Kimmel, who was indefinitely suspended on Wednesday.

The row started after Kimmel appeared to suggest in his monologue on Monday night that the alleged gunman charged with murdering Kirk was a Maga Republican, although authorities in Utah have said the suspect was 'indoctrinated with leftist ideology'.

Before ABC's decision, Carr said there would be consequences if Kimmel stayed on air. The FCC chairman said that Kimmel was 'appearing to directly mislead the American public' in his on-air remarks.

On his podcast Verdict with Ted Cruz, the senator emphasized on Friday that he hated what Kimmel said about Kirk, and he is 'thrilled that he was fired'. He also said Carr was 'a good guy'.

'But what he [Carr] said there is dangerous as hell,' Cruz added. 'And so he threatens, explicitly, we're going to cancel ABC's licence. We're going to take them off the air so ABC cannot broadcast anymore. He says we can do this the easy way, or we could do this the hard way, yeah. And I got to say that's right out of Goodfellas.'

Cruz warned that if the government gets into the business of bans and regulating what the media says 'that will end up bad for conservatives'.

In the Oval Office on Friday, President Donald Trump defended Carr and said 'I disagree with Ted Cruz', who is ordinarily one of his staunchest allies.

Republicans in Congress have generally been toeing the party line with their response to Kimmel's suspension as the nation is shaken by the political and cultural aftershocks of Kirk's killing.

Senator Jerry Moran, a Republican from Kansas, warned of the implications for free speech in this context, stating, 'The conservative position is free speech is free speech, and we better be very careful about any lines we cross in diminishing free speech.'

Kimmel has not publicly commented about his suspension, but his late-night colleagues - including Jon Stewart, Jimmy Fallon, and Stephen Colbert - responded with a show of solidarity.

The controversy continues to unfold as lawmakers grapple with the complex implications of media regulation, free speech, and the responsibilities of public broadcasting.