A historian who has accurately predicted every presidential election since 1984 -- including Donald Trump -- believes the 45th president will not be able to finish his four-year term.
Allan Lichtman, a history professor at American University, told CBC that Trump's decision to fire FBI director James Comey could be considered grounds for impeachment -- although he's not sure Vice President Mike Pence would take Trump's place.
"The media has given Mike Pence a huge pass," Licthman said. "He lied about Gen. (Mike) Flynn, he lied about the reasons why Comey was fired, and the media says he was misled. We don't know that he was misled, that's a supposition on the part of the media. In fact, maybe he was part of this whole operation right from the start, and maybe he's in it as deeply as Donald Trump -- we do not know, and an impeachment investigation needs to look at Mr. Pence, as well."
He noted that Comey was fired one day after former acting attorney general Sally Yates' testified before Congress, and the president admitted the FBI director's dismissal was related to the Russia investigation.
"That's at least borderline obstruction of justice," Lichtman said. "Add to that the fact that the White House pretty transparently conspired earlier with Rep. (Devin) Nunes to derail the House investigation into possible Russian collusion. Putting it all together, and you've got a probable cause case for obstruction of justice -- and there's only one way of dealing with that, constitutionally."
Lichtman said the Constitution's framers established impeachment to peacefully protect democratic institutions from "a rogue president."
"If Democrats stand firm, it would only take some two dozen Republicans to shift -- that's just 10 percent of Republicans in the House," he said.
He cautioned Democrats against pushing for a special prosecutor, because the president could hire and fire that investigator, and instead pursue an impeachment investigation in the House Judiciary Committee.
"It would be conducted by another branch of government, it would be entirely independent of Donald Trump and it would have the clout to keep Donald Trump from obstructing it," Lichtman said.