George Soros isn't sending Donald Trump best wishes on the eve of the inauguration.
Speaking at a Thursday night Davos dinner, Soros called Trump a "conman, an imposter, and a would-be dictator."
"I think Trump will fail," Soros said.
The dinner talk was billed a one-on-one conversation with the billionaire investor, but it quickly became a Trump whack-a-thon with Soros throwing one put-down after another.
Most of the swings were jabs, but Soros did back up his prediction that Trump's presidency will be a failure, and it was an interesting one, because it didn't appear to be based on ideology alone. Soros backed Hillary Clinton in the election and he is one of the Democratic party's biggest donors.
Soros called Trump's ideas contradictory and his choice of cabinet members lousy.
"He's picked three chiefs of staff instead of one," said Soros. What's more, Soros said even the members of his cabinet don't seem to have similar views on how the president-elect should govern. "His cabinet comes from various establishments," said Soros. "There will be infighting."
Soros pointed to Trump's position on trade as one of his contractions. Soros said Trump has called for stimulus efforts that will boost the economy immediately. But Soros said starting a trade war with China will slow the economy, not boost it.
(Related: Soros Has Lost $1 billion on the Trump Bump)
What's more Soros predicted that the market's Trump high will soon turn into a hangover. He called Trump unpredictable and unprepared, and said that combination will end being bad for the market.
Outside of Trump, Soros said that he thought Brexit won't be as hard as many suspect. He said British voters were reacting to the fact that EU rules are too complicated, and will likely need to be reformed. "I think by 2019 to 2020, Britain will leave the EU on a Friday," said Soros. "But rejoin on a Monday."
On Trump as president: "Trump stands for a form of government that is a dictatorship or mafioso state. He would be a dictator if he could get a way with it."
On Trump and China: "Trump will do more to make China look respectable in the eyes of the international community than China could have ever done on its own."
On Trump and markets: "Long-term investors don't like uncertainty. I don't think the market will do very well [under Trump]."