Fox News host Shepard Smith had been on air for all of a minute on Tuesday when the angry tweets started piling up.

Smith had resumed his ongoing critique of Donald Trump, mocking the White House's complaints about anonymous sources and the president's refusal to release his tax returns.

The anchor's Twitter feed, meanwhile, was flooded with calls for his job.

More than a few observed that Smith, who has been with Fox News since its inception in 1996, should take his broadcasting talents elsewhere.

"Go to CNN," one tweet said.

"Time to change the channel to DR. Phil," said another.

"He's an arrogant, smug know it all," said a third person, who claimed to have already turned him off. "He doesn't even pretend to have any respect for POTUS."

Such is life for a Fox anchor holding the president accountable. On a channel where coverage of the new administration has been sympathetic, sometimes even fawning, Smith has distinguished himself as the most consistently adversarial voice.

And that has made him perhaps the least popular host among a faithfully pro-Trump audience.

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In January, Smith came to the defense of CNN's Jim Acosta after he was chastised by Trump at a press conference. Neither Acosta nor any other journalist, Smith said, "should be subjected to belittling and delegitimizing by the president-elect of the United States."

In February, Smith was flabbergasted by another Trump press conference, in which the president again needled Acosta and dodged questions about connections to Russia.

"It's crazy what we're watching every day," Smith said on the air. "It's absolutely crazy. He keeps repeating ridiculous, throwaway lines that are not true at all and sort of avoiding this issue of Russia as if we're some kind of fools for asking the question."

On Friday, Smith took on Trump once again after the White House blocked CNN and several other news organizations from attending an off-camera press briefing known as a gaggle.

The decision came after CNN, which Trump regularly maligns as "fake news," reported that the FBI had rejected a White House request to knock down media stories about alleged communications between the president's associates and the Russian government.

"CNN's reporting was not fake news," Smith said.

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In each case, Smith was met with vitriol from the president's defenders on Twitter and in the media.

NewsBusters, a conservative media watchdog website, called Smith "unhinged." "Fox News' Shep Smith Scolds Trump For Being Mean to CNN's Jim Acosta," read a headline last month on the staunchly pro-Trump Breitbart News.

Fox News executives have never seemed bothered by Smith's occasional apostasy. Smith said last year that Fox News founder Roger Ailes, who was ousted amid sexual harassment allegations, was "very fatherly and mentorish."

A spokeswoman for the channel did not respond to a request for comment for this story.

Smith's critics have drawn unfavorable comparisons to a former colleague who used to get under the president's skin.

But there are notable differences between Smith and Megyn Kelly, who left Fox for NBC News earlier this year. For all her feuds with Trump, Kelly's 12 years at Fox included plentiful examples of the liberal-bashing that has been the channel's hallmark.

Smith, on the other hand, has repeatedly broken with Fox's conservative orthodoxy -- long before Trump became president.

In 2014, Smith said on air that the same people pressuring President Barack Obama to take military action in Iraq had assured the public that the 2003 invasion would be "quick" and "easy."

After more than a dozen Republican governors signed executive orders blocking refugees from Syria and elsewhere in 2015, Smith delivered an emotional on-air monologue.

"In the face of terror, will we panic, or be calm and deliberative in approach?" Smith said. "Confronted with those who want to change our way of life, will we abandon our freedoms and the rights granted to us by the creator, or will we welcome huddled masses yearning to breathe free?"

But the biggest difference between Smith and Kelly might be in the responses they have elicited from the president himself. Kelly was repeatedly insulted by Trump during the campaign. His treatment of Smith has been mild.

"Boy is this guy @ShepNewsTeam tough on me," Trump tweeted in 2015, 12 months before he was elected president. "So totally biased. As a reporter, he should be ashamed of himself!"