Trump falsely claimed that the U.S. is “the only country in the world” with such a path to citizenship. More than 30 nations, including Canada and Mexico, have similar policies in place.

Trump’s statements come a week before the midterm elections and appear aimed at once again riling up the Republican base. It’s unclear how serious he is, but if he issues such an executive order, it almost certainly would end up in the courts, where it would face extremely long odds of surviving.

There’s also the matter of subsequent presidents, any of whom may reverse their predecessors’ orders, just as Trump did with a number of President Barack Obama’s more contentious orders, like the Deferred Action on Childhood Arrivals immigration program.

Ryan filed suit against Obama on behalf of the House of Representatives over DACA in early 2016. Ryan later said during a sit-down interview with HuffPost that he would “sue any president that exceeds his or her power.”

He did not bring up the prospect of suing Trump on Tuesday, but that would be the logical response if the president issues an order ending birthright citizenship. Though such speculation is pointless for a number of reasons. For one, Trump often raises the possibility of doing something, only to lose interest. And if he issues such an order, Ryan likely won’t be there when it drops.