Donald Trump could be the first president to be successfully impeached, according to Professor Ronald L. Feinman. REUTERS/Kevin Lamarque Donald Trump's presidency is likely to be the second shortest ever, a leading historian and author has claimed.

Professor Ronald L Feinman predicted that the former reality TV star will stay in the top job "between the 31 days of William Henry Harrison in 1841," who died pneumonia and the "199 days of James A. Garfield in 1881," who died 79 days after he was shot by an assassin "after terrible suffering and medical malpractice."

Even if his time in office is "dragged out," Feinman predicted that Trump is unlikely to last the 16 months and 5 days of 12th president Zachary Taylor, who died of a digestive ailment while Head of State in 1850.

The 20th-century American history professor, who recently published a book about the unfortunate fates of US leaders, added that he thought the "Pence Presidency" was inevitable. He was referring to Trump's Vice President, Mike Pence, who would take over if Trump was to leave the leadership.

In a blog post, he added that he thought it was likely that Trump will be impeached or forced to resign in a matter of weeks.

Feinman predicts Trump won't last as long as President James A. Garfield, who died 199 days into office. Wikimedia His prediction comes shortly after the White House admitted the President was told several weeks ago that his National Security Adviser Michael Flynn had not told the truth about a telephone call with a Russian diplomat.

The news fuelled broader concerns about his closeness to Russian President Vladimir Putin and the role his country may have played in helping Trump's election.

Feinman, who teaches at Florida Atlantic University, suggested the businessman turned politician is more generally unsuitable for office.

"Many foreign policy professionals are shaking their head at Trump's inappropriate behavior and language every time he speaks in public, or issues a Twitter comment, and his instability and recklessness," he said, citing Trump's decision to hold a security meeting over the North Korean missile test in a public space in earshot of other people as "a sign of his failure to act responsibly."

"The fact that Vice President Mike Pence played a major role in pushing Flynn out is a sign that Pence is already asserting himself with Trump," he said, adding the Vice President often appears uncomfortable with Trump's "freewheeling and careless behavior."

No US president has ever been successfully impeached, although an attempt was made to Bill Clinton but he was acquitted by the Senate.

Richard Nixon also resigned before he could be impeached for serious wrongdoing in the Watergate scandal.