BREMMER: Donald Trump 'is a threat to US political institutions and values'

Donald Trump is often criticized for his divisive rhetoric, but geopolitical expert and Eurasia Group President Ian Bremmer thinks it could threaten the very foundation of US politics and values.

"I believe @realDonaldTrump is a threat to US political institutions & values," Bremmer tweeted. "I've never felt that way about a presidential nominee."

Bremmer, a non-partisan analyst whose firm focuses on geopolitical risk, expanded on that thought in an email to Business Insider. He said he viewed Trump's "authoritarianism" as the true danger in his potential administration.

"Trump's authoritarianism is the danger. It's the way he deals with enemies in business, politics and the media," Bremmer said. "The way he uses fear to gin up support among the dispossessed and downtrodden. The way he idolizes international 'strongmen' while telling our allies that they're transactions on a balance sheet, nothing more, nothing less."

Trump has been criticized for speaking favorably of Russian President Vladimir Putin and saying that US allies need to pay more for their own defense.

"There's a reason his admirers are Hungary's [Prime Minister Viktor] Orban, France's [far-right politician Marine] Le Pen, Russia's Putin, even Kim Jong Un," Bremmer said. "These are not people who want to make America Great Again."

Bremmer said the US has always been a "force for good" in the world and that Trump could endanger that quality.

"America desperately needs a president who will lead by example," Bremmer said. "Trump would lead by revulsion."

Trump represents "a rejection of America's core values of inclusion, integration and hope" and "an effort to divide society at home ... and societies abroad."

Bremmer said that while he doesn't support Trump's rival, Democratic presidential nominee Hillary Clinton, he thinks Trump would be more damaging to the country.

"To be clear, I'm no Clinton supporter," Bremmer said. "I'm not registered with a political party. But I've never seen a nominee - from either party - who I thought represented such a danger to everything the United States stands for. I consider it an obligation to make my voice heard accordingly."