FILE PHOTO: White House Chief Strategist Stephen Bannon speaks at the Conservative Political Action Conference (CPAC) in National Harbor, Maryland Thomson Reuters

Former White House chief strategist Steve Bannon reportedly has told people he thinks President Donald Trump has just a 30% chance of completing his four-year term.

The detail came in an explosive report from Vanity Fair's Gabriel Sherman on Wednesday that cited several sources close to the president.

According to two of the sources, Bannon warned Trump several months ago about the possibility of getting removed from office via the 25th Amendment, prompting Trump to ask, "What's that?"

A stipulation of the 25th Amendment allows the vice president and a majority of the Cabinet - that is, 13 of 24 Cabinet members - to vote the president out of office. Bannon reportedly considered it a more likely scenario than Trump's impeachment.

Political observers have questioned for months whether Trump will serve the entirety of his four-year term. Speculation has only increased since Sunday, when Republican Sen. Bob Corker issued a scathing critique of Trump to The New York Times in which he called the White House "an adult day care center" and said the president could set the country "on the path to World War III."

Bannon, the former Trump campaign CEO and close ally to the president, left the White House in August amid reports that Trump believed Bannon was leaking information to reporters and being given credit for Trump's successes.

Bannon has resumed his perch atop the far-right site Breitbart, where he and allies have been staunchly critical of Republican leaders, including Corker this week. A Bannon-aligned group is preparing to back primary challengers to several incumbent Republican senators in the 2018 election cycle.

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