Elon Musk and President Trump‘s epic, “Mean Girls”-esque breakup isn’t just entertaining, it’s a giant opening for Democrats to win back voters … according to Bill Maher, who fears the party’s gonna miss the boat. Again.

Maher dropped a “new rule” for Dems Friday night on his HBO show ‘Real Time’ … as he urged left-leaning leaders to pull the plug on “idea-a-thon” think tanks, and focus on winning back guys like Musk and Joe Rogan.

In the wake of Elon choosing the nuclear option — aka the ‘Epstein files’ — in his war with Trump, Bill sees a chance for the Dems to swoop and scoop up former liberal thinkers who jumped to the GOP … a move he says they gotta stop calling, “going to the dark side.”