"Bigotry seems emboldened," Bush said in New York at a forum put on by the George W. Bush Institute. "Our politics seems more vulnerable to conspiracy theories and outright fabrication."

He slammed a discourse that seems "degraded by casual cruelty," disagreement that "escalates into dehumanization" and a "nationalism distorted into nativism."

Bush, however, also criticized the kind of liberal populism that led to Bernie Sanders' rise on the left.

"There are some signs that the intensity of support for democracy itself has waned, especially among the young who never experienced the galvanizing moral clarity of the Cold War or never focused on the ruin of entire nations by Socialist central planning," Bush said. "Some have called that democratic deconsolidation. Merely it seems to be a combination of weariness, frayed tempers and forgetfulness."