Fox News host Shep Smith launched a blistering attack on Donald Trump Monday, questioning what the GOP presidential nominee’s real motives are.

Smith railed against Trump for pandering to his voter base by attacking his Democratic rival Hillary Clinton during Sunday night’s presidential debate. He also criticized the brash businessman for failing to court undecided voters who wanted to hear substantive arguments, as Trump vowed to jail Clinton if he were elected.

“It might have been bordering on unconstitutional, maybe even something almost definitionally fascist,” Smith said of the declaration. “This, ‘If I get elected, I’m going to prosecute my political opponent,’ that’s never been done in the history of the United States.”

Smith speculated that Trump’s debate performance was not one of a candidate attempting to win the general election, but perhaps of a person vying for a media network. “It’s all set up not as a guy who’s trying to win what’s left to get, but a guy who has another agenda,” he said.

Rumors have been circulating for months that Trump’s back-up plan if he loses in November will be to start a media network catered to his voter base.

Check out the whole exchange in the video above.