The News Corporation headquarters, owner of Fox News, stands in Manhattan. Spencer Platt/Getty Images

He could have spent Sunday tweeting about truly consequential issues such as condemning white nationalism in the wake of the New Zealand mosque shooting, or championing diversity and tolerance.

Instead, president Donald Trump chose to go on a tweet storm where he blasted two Fox TV journalists who slammed his emergency declaration while demanding his favorite Fox journalist, Jeanine Pirro, be put back on air. He also insulted the late Senator John McCain -- again.

What was new or news in all this was Trump’s rage against Fox News weekend anchors, Arthel Neville and Leland Vittert. Neville is currently the weekend anchor at Fox News Channel while Vittert is a news presenter at the same show.

This is the first time he’s gone after these people, and it marks a departure from his usual attacks on his arch critic at Fox, Shepard Smith. Trump, by the way, also took a swipe at Smith in the same tweet where he blasted Neville and Vittert.

The cause of Trump’ latest meltdown? Neville and Vittert had the nerve not to support Trump’s flawed reason for declaring a national emergency to build his border wall with Mexico.

To be sure, Neville and Vittert have been critical of Trump before, but the president let it pass -- until now.

In a segment on Fox News' "America's New HQ" Sunday, Vittert questioned the constitutionality of the president's proposed border wall with Mexico.

"Article one (of the Constitiution) clearly says the power of the purse is with Congress," said Vittert. "If all of a sudden you're using executive action and emergency powers to move that funding around, how is that not changing law?"

She also called into question if Congress should be handing over more of their power to the president.

"Is this precedent worth it, to get a border wall or get funding for part of a border wall, for Congress to continue to give away more and more authority?" asked Vittert.

In the past, Vittert and Neville have been critical of the of Trump's reasoning for a wall at the southern border with Mexico.

"It's very difficult to try and fact check the president's remarks [on the matter] in real time" Vittert said back in January on the show.

Vittert’s Sunday diatribe seems to have hit a special nerve in Trump, who tweeted after the show: “Were @FoxNews weekend anchors, @ArthelNeville and @LelandVittert, trained by CNN prior to their ratings collapse. In any event, that’s where they should be working, along with their lowest rated anchor, Shepard Smith!”

Contrast to Trump’s indignation at Vittert and Neville was his fulsome praise of Pirro, whose show was yanked after she made unabashedly Islamophobic comments on March 9. Her racist remarks came a week before a racist Australian murdered 50 Muslims in New Zealand on March 15.

“Bring back (Judge Jeanine) Pirro,” Trump tweeted from the White House, before a St Patrick’s Day service at St John’s Episcopal Church. Trump’s tweet also said Fox should “be strong and prosper,” rather than “be weak and die.”