President Donald Trump on Monday slammed Fox News after his once-favorite network released a new poll that shows him trailing against many of his potential 2020 Democratic rivals.

The poll shows Trump losing to former Vice President Joe Biden by 10 points and Sen. Bernie Sanders (I-Vt.) by 9. It also shows Sen. Elizabeth Warren (D-Mass.) Sen. Kamala Harris (D-Calif.) and South Bend Mayor Pete Buttigieg with very small leads over Trump.

“Something weird going on at Fox,” the president tweeted. “Our polls show us leading in all 17 Swing States.”

It’s not clear what internal polls he was referring to. However, Trump reportedly fired some of his own pollsters after leaked internal polls showed him trailing Biden in key states.