Treasury Secretary Steven Mnuchin called on Congress to give President Trump a line-item veto saying that it is the only way to avoid Democrats filling a budget bill with discretionary spending. The only problem? The line-item veto was ruled unconstitutional by the Supreme Court 20 years ago and Fox’s Chris Wallace said exactly that, leading to a bit of a tense exchange on Fox News Sunday.

“I think they should give the president a line-item veto,” Mnuchin said. Wallace answered: “That’s been ruled unconstitutional by the Supreme Court.” At that point Mnuchin seemed to dismiss the concern and said, “Well, again, Congress could pass a rule, okay, that allows them to do it.” Wallace quickly corrected him: “No, it would be a constitutional amendment.” At that point an evidently exasperated Mnuchin ended the discussion: “Chris, we don’t need to get into a debate … there’s different ways of doing this.”

To be fair, Mnuchin was only following his boss’s lead after President Donald Trump specifically called on Congress to give him “a line-item veto for all govt spending bills.” Trump made the call after expressing anger over signing a $1.3 trillion omnibus government spending bill even though he opposed much of it but insisted it was necessary on national security grounds.

As a matter of National Security I've signed the Omnibus Spending Bill. I say to Congress: I will NEVER sign another bill like this again. To prevent this omnibus situation from ever happening again, I'm calling on Congress to give me a line-item veto for all govt spending bills! https://t.co/kYwMk5AE5k — Donald J. Trump (@realDonaldTrump) March 23, 2018

The Supreme Court ruled six-to-three in Clinton v. City of New York that the line-item veto was unconstitutional because it gave too much power to the president to amend laws approved by the legislative branch. “There is no provision in the Constitution that authorizes the president to enact, to amend or to repeal statutes,” noted the majority opinion written by Justice John Paul Stevens.