Jelly Roll spent Monday night guest-hosting "Jimmy Kimmel Live!" on ABC — and used the opening monologue to deliver a string of jokes about President Trump that blindsided much of his own fan base.

The country star, one of several guest hosts filling in while Kimmel takes his summer break, mocked Trump's appearance at the "Freedom 250" IndyCar event in Washington, D.C., joking about the president fumbling a ceremonial flag wave. Referencing a Washington Post report on Trump's recent weight gain — said to be roughly 14 pounds, putting him near 240 pounds — Jelly Roll, who has spoken publicly about losing about 300 pounds himself, quipped that the number meant "I've lost an entire Donald Trump," before adding a jab about the president's approval ratings.

Fans Weren't Expecting It

The bit caught much of his audience off guard. Social media reaction, cited by TVInsider, included comments like "Isn't Jelly Roll MAGA?" and "I thought Jelly Roll loved Trump" — a reaction rooted in assumptions about his largely country and rural fan base.

I'VE LOST AN ENTIRE DONALD TRUMP.

Jelly Roll has previously described himself as politically unaffiliated, saying, "I am neither Democrat nor Republican," and positioning himself as a musician first rather than a political figure. That framing made Monday's monologue land as more surprising than it might have from a more overtly political comedian.

Billboard, Rolling Stone and TheWrap all covered the monologue as a standout moment of his guest-hosting run, with TheWrap rounding up the wave of surprised fan reaction across social platforms.

Jelly Roll is set to continue guest-hosting "Jimmy Kimmel Live!" for the rest of the week before Kimmel returns from hiatus. Whether he keeps the political material in future nights — or dials it back after the reaction — remains to be seen.