Neal Katyal warns the president-elect that even a conservative Supreme Court likely won't be on board with this part of his agenda.

Former acting Solicitor General Neal Katyal said at least some of Donald Trump’s plans will run afoul of the courts ― even one with a conservative majority.

“That Republican majority has at times stopped some of Trump’s excesses,” he told MSNBC’s Jen Psaki on Sunday, referring to instances in which the court has already ruled against him, such as in a census case as well as in dozens of cases linked to the 2020 election.

He predicted that the court likely would not support Trump’s plan to use the Alien Enemies Act of 1798 as a basis for mass deportation of undocumented immigrants as it requires an “invasion or predatory incursion, which is very hard to say is going on.”

Trump has also vowed to end birthright citizenship via executive order.

Katyal said the law is even clearer there given that it’s in the Constitution.

“Last I checked, the president can’t override the Constitution,” he said. “The Fourteenth Amendment is as clear as day that there is no way he can do that. If he tries that, he will lose in court every day of the week.”