The tweets put FCC Chair Ajit Pai in a bind. Trump's statements angered not just liberals and press freedom advocates, but some of Pai's more conservative, pro-market allies as well.

Pai could probably calm the industry and people across the political spectrum by assuring them that the agency won't violate democratic norms by targeting stations for political reasons. But thus far he hasn't issued an official statement or even a tweet about the president's tweets.

The FCC can't revoke a broadcasting station's license simply because it ran a story the president didn't like or says is untrue. In theory, the agency could try to build a case against stations for other reasons, such as the obligation for license holders to serve the public interest, says Matt Wood of the advocacy group Free Press. But there's little precedent for revoking licenses in recent years and it's not clear that any revocations would hold up in court.

Each station is licensed separately, so each revocation would face a separate legal challenge. Most NBC affiliate stations are not owned by NBC owner Comcast. For example, Sinclair Broadcast Company, usually seen as a Trump ally, owns several NBC affiliate stations across the country, including ones in Las Vegas, San Antonio, and Syracuse, New York. To get every NBC affiliate off the air, the FCC would have to convince courts that each individual revocation was justified.

"I think Chairman Pai is precariously balancing his desire not to anger the president with his desire not to anger the broadcast industry, which he has assiduously courted," says former FCC special counsel Gigi Sohn. "He certainly doesn’t want to attract the president’s ire."

This isn't the first time Pai has been asked about the president's tweets. During a Senate hearing in March, Democrats asked Pai whether he agreed with Trump's statements that the press was the enemy of the American people. Pai didn't give a straight answer, but did later pen a letter saying that he wouldn't take action to violate the free speech of journalists, even if the president asked him to. In the letter, he avoided criticizing Trump or condemning the president's tweets.

Unlike Reince Priebus, Steve Bannon, James Comey, or other federal officials forced out of their jobs by Trump so far this year, Pai's job is relatively safe. FCC commissioners are appointed by the president, but cannot be removed by the president. The Senate just confirmed Pai for another five-year term. But the president also appoints the commission's chairman, so Trump in theory could demote Pai and name another chairman. Neither of the other Republican commissioners, Brandan Carr and Michael O'Rielly, has responded publicly to Trump's tweets yet. The FCC did not respond to a request for comment.

Even as Pai tries not to anger the president, he risks alienating other allies. Trump's call for less partisanship on network news sounds like a call for a return of FCC rules known as the "Fairness Doctrine," which from 1949 until they were overturned in 1987 dictated that broadcasts cover both sides of news stories.

Conservatives generally cheered the end of the doctrine. It opened the door for conservative radio commentators like Rush Limbaugh to build their careers. Some right-leaning groups have long feared the doctrine's return.

In a statement, Randolph May, president of the free-market think tank Free State Foundation, said that while he has many disagreements with NBC's editorial judgments, he believes that challenging a company's broadcast licenses over editorial disagreements would chill the media's First Amendment rights.

"President Reagan’s FCC got rid of the notorious Fairness Doctrine to get the government out of the business of judging whether programming was 'balanced’ and ‘fair,’" May said. "I don’t think he would have urged challenges to FCC licenses based on disagreement about program content decision---and I strongly suspect current FCC Chairman Ajit Pai agrees based on his understanding of the First Amendment."

Perhaps Pai hopes his actions can make up for his lack of words. Under his leadership, the FCC has loosened media-ownership rules that restrict the number of stations that broadcasting companies can own in particular markets and is poised to relax them further. And his plans to reverse Obama-era net neutrality rules should please Comcast.