Former top presidential adviser Steve Bannon says he has "zero" doubt right now that President Donald Trump will run for a second term in 2020.

However, the ex-chief strategist tells CBS News Correspondent Seth Doane that 2019 will not be an easy year for the president.

"I believe that we're going to enter into an extraordinary time in American politics," Bannon warned.

"We've allowed the Democrats, because they take control of the House, to weaponize a whole bunch of investigations. They're going to be able to weaponize the Mueller report. 2019's going to be quite vitriolic."

CBS News has learned that Mueller's report is expected to be turned in sometime after next week to Attorney General William Barr.

However, Bannon sees a graver threat to the president's reelection beyond the Mueller probe. Investigations continue by federal prosecutors in the Southern District of New York and elsewhere, including a probe into Trump's inaugural committee.

"I think we're, in the United States right now for the next four or five months, going to really be into quite a vitriolic time," Bannon said.

Former White House Chief Strategist Steve Bannon spoke Saturday with CBS News Correspondent Seth Doane in Rome.

More from Doane's interview will air Sunday on "Face the Nation" with Margaret Brennan. Click here to check your local listings.



And for the latest from "Face the Nation," follow us on Facebook, Twitter, or Instagram.