A new survey released Sunday reveals just how impenetrable President Donald Trump's level of support among regular Fox News viewers is, and suggests that a mass mobilization among those who support impeaching and removing Trump from office may be the only way Congress will finally hold him to account.

The Public Religion Research Institute (PRRI) polled 2,000 people and found that among Republican voters who use Fox News as their regular news source, 55 percent said that no action taken by Trump could cause them to oppose him.

The findings bolstered the president's statement, made during the 2016 election, that he "could stand in the middle of Fifth Avenue and shoot somebody and [he] wouldn't lose any voters."

But the results varied for Republicans who don't regularly turn to Fox for their news; only 29 percent of them said there was nothing Trump could do to lose their approval, and only 39 percent said they strongly approve of the president.

Ninety percent of Republicans who don't watch Fox regularly said they don't support impeachment and removal of Trump from office, compared to 98 percent of those who do watch Fox.

The former number "is overwhelmingly high," Washington Post columnist Greg Sargent wrote, "but suggests that among this group, at least, Trump could suffer losses on the margins as the inquiry turns up worse revelations."

As journalist Mehdi Hasan wrote on Twitter on Tuesday, Fox News is "not just a conservative news outlet. It is a propaganda channel for the president and his party, and there is no liberal or centrist equivalent to it."

This is what a lot of well-meaning liberals don’t understand about Fox - it’s not just a conservative news outlet. It is a propaganda channel for the president and his party, and there is no liberal or centrist equivalent to it. https://t.co/wblDyfuS8p — Mehdi Hasan (@mehdirhasan) October 22, 2019

Hasan later highlighted an on-air remark from Fox News host Mark Levin that "there hasn't even been a hint of scandal" since Trump took office as further proof that the network offers "just pure and endless propaganda."

I said it last night and I will say it again: Fox News doesn’t even pretend to be a news channel anymore and is now just pure and endless propaganda on behalf of this scandal-ridden President. https://t.co/8gheS4by3n — Mehdi Hasan (@mehdirhasan) October 22, 2019

Trump notoriously watches several hours of Fox News on a daily basis and has been known to regularly speak with host Sean Hannity after Hannity ends his nightly show.

As Sargent wrote in the Post, the network's coverage of Trump's recent plan to host next year's G7 summit at his resort in Doral, Florida—a violation of the Constitution's Emoluments Clause—played a role in reversing the president's decision:

Trump pulled the plug on his corrupt scheme to host the Group of Seven summit at his Doral resort after getting informed that some moderate Republicans—the ones he needs to keep in line on impeachment—didn't want to defend it, amid indications that it would become part of the case for impeachment. He also witnessed some Fox News personalities disapproving of it...That's when Trump concluded the jig was up on Doral, the New York Times reports.

According to Sargent, with both Trump and his most loyal supporters tuning in to Fox News on a regular basis, the network serves to reassure his base that Trump has done nothing wrong to deserve the impeachment inquiry House Democrats have initiated, while protecting the president from real accountability:

It's difficult to say whether Republicans watch Fox because they're already in lockstep with Trump, or whether they're inclined that way because of what Fox tells them. But these things seem to reinforce one another—and that may prove a significant factor in keeping GOP lawmakers in line behind him. [...] This hermetically sealed-off version of reality has created a space in which Republicans are backing Trump because he's only done right.

In recent days, Trump critics including New York Times columnist David Leonhardt and Crooked Media editor Brian Beutler have argued that with Fox News at the president's disposal and Fox's Republican viewers showing no sign of abandoning Trump, the president is essentially protected from impeachment unless a mass mobilization is begun by the at least 50 percent of Americans who do support his removal.

"The Fox effect is protecting Trump from removal, and mass mobilization is likely the only way for impeachment supporters to overcome it," Beutler tweeted.

Leonhardt on Sunday wrote that Fox's hold on Republican voters makes it increasingly unlikely that their Republican representatives in Congress will defect and announce their support for impeachment.

"Protest may be more important than in the past, because the elite institutions that helped bring down Richard Nixon, like political parties and the national media, are weaker today," he wrote.

A mass protest "can wake up more Americans to the gravity of the situation," Leonhardt added. "It can mobilize progressives to work as hard as they did during the 2018 midterms. It can confront congressional Republicans with their cowardice."