Billy Eichner Says Donald Trump is an 'Evil Piece of S***'

Billy Eichner cannot contain his rage over Donald Trump, and the most recent trigger is the Trump Administration's move to rigidly define gender.

Eichner's contempt for Trump is palpable ... this in the wake of the administration's move to define gender as a "biological, immutable condition determined by genitalia at birth."

Our photog got the "Billy on the Street" star at LAX Sunday, and he doesn't sound overly confident that a blue wave will sweep the country next month.