"I want my fellow Americans to recognize that 'not Trump' will never be enough," one Gavin Newsom critic told us.

The revelation drew laughter from a summit audience but prompted the California governor to warn: “This is serious, guys. This is serious."

"I want my fellow Americans to recognize that 'not Trump' will never be enough," one Gavin Newsom critic told us.

"I want my fellow Americans to recognize that 'not Trump' will never be enough," one Gavin Newsom critic told us.