Tucker Carlson said Tuesday on "Special Report" that there is likely a backstory behind why U.N. Ambassador Nikki Haley announced her resignation.

"Everything is [eventually] revealed, nothing is hidden," Carlson said. "Ultimately, everyone I know believes there is a story there. No one knows what it is."

Carlson said that despite being one of the most popular members of President Trump's cabinet, Haley has a history of being diametrically opposed to the president in a lot of ways.

He said Haley repeatedly attacked Trump during the 2016 campaign, and was not an early fan of his.

A 'Dead Heat?': NJ GOP Candidate Hugin Says Race Against 'Chaotic' Menendez Could Be Surprise

Gutfeld: Left-Wing Mobs of 'Angry Losers' Attack Civilians in Oregon

"The deeper question is why Trump hired Nikki Haley in the first place," he said.

Carlson said Haley embodies the "2002 neoconservatism" that Trump often rails against, and has brought the U.S. "closer to conflict" with several countries -- against Trump's own foreign policy platform.

He said that Haley is however "hyperarticulate" and "impressively unintimidated."

The Special Report panel also reacted to claims her resignation was a "5-dimensional chess"-type plot to have her take Sen. Lindsey Graham's (R-S.C.) seat and shift Graham into the White House cabinet.

Watch more above.

'The Definition of Feminism': Lara Trump Says Collins Stood Up to Left-Wing 'Mob' by Voting for Kavanaugh

Left-Wing Website Editor Mocks Steve Scalise for Warning About Political Violence