Anthony Scaramucci, Donald Trump’s former communications director, believes the US president is a "political genius" who used Twitter to win the election.
Addressing the Oxford Union on Monday night, Mr Scaramucci discussed how Mr Trump defeated Hillary Clinton in November, despite the Democratic nominee's greater financial clout.
"I firmly believe that President Trump, without the tool of Twitter, likely would have not won," Mr Scaramucci said.
"Trump was outspent by Clinton by 1.7 times, she had 2.4 more personnel than us. It’s not clear to me that the money is as important as the ideas.
"You have to accept he’s a political genius. In 19 months, he went from 0 to POTUS (President of the United States). You can’t say there wasn’t some level of genius in terms of his judgment."
Praising Mr Trump's electoral strategy, he highlighted the Democrat-leaning state of Wisconsin.
"How many times did Clinton go to the state of Wisconsin? 0. The president went 16 times," he noted.
Mr Trump has caused outrage with his personal attacks on Twitter and for using it to discuss foreign policy. Last month, North Korea said Mr Trump had "declared war" after the president said leader Kim Jong-un "won't be around much longer".
"He’s definitely not a sociopath," Mr Scaramucci said. "He is way more contemplative, more thoughtful, more of a person who doesn’t want to bring about wars than you would think.
"When the president feels he’s well defended his tweets are more focused on public policy, when he feels he’s not well defended you get things like Mika’s facelift," he added, referring to the president's particularly personal attack on television host Mika Brzezinski.
Profile | Anthony Scaramucci
Mr Scaramucci, who was fired after just 11 days in the White House, said he thought he would last longer than that - but not much more.
"The moment I was declared, the knives got longer and longer," he said. "I didn’t think I’d last more than 30 to 60 days in the role."