Comedian Robert Klein Comes Unhinged, Squares Off with Donald Trump Supporters

Robert Klein ain't cracking jokes when it comes to Donald Trump -- he came unhinged, ranting about the President's numerous scandals ... then came face-to-face with some vocal Trump supporters.

The scene was unreal Thursday night outside Craig's in WeHo -- the legendary comedian went OFF when we asked about Trump's meeting with Kanye West. He quickly pivoted the convo away from Ye and launched into a tirade about Paul Manafort, Russia and Stormy Daniels ... the whole nine.

Perfect timing for a couple of Trump fans to approach! Warning: Robert's super salty here and drops so many f-bombs, DMX might blush.

He's making zero effort to hide it ... Robert's definitely longing for the days of Barack Obama.

The bad news for him is ... we all know Obama's not coming back. Just ain't gonna happen, Bob.