() President Donald Trump signed a new executive order on election reform this week, which makes changes to voting policies around citizenship and mail-in ballots.

The law would require proof of citizenship to vote, bars noncitizens from donating to certain elections, requires states to turn over voter lists to Homeland Security and the Department of Government Efficiency for review and prohibits states from counting mail-in ballots that arrive after Election Day.

David Levine, senior fellow at the University of Maryland’s Center for Democracy and Civic Engagement, joined to discuss legal hurdles the order is likely to face.

Levine noted that the order is building on the Help America Vote Act, which was passed by Congress regarding voting rights and proof of citizenship.

“It’s quite clear that attestation of citizenship is all that’s required and that’s required by the National Voter Registration Act of 1993,” he said.

There is also the broader question of executive authority. Congress is meant to pass laws, per the U.S. Constitution, and the executive is supposed to enact them while courts interpret them.

“Additionally, there are a number of things in this executive order that raise questions with regards to separation of powers,” Levine said.

Elections have traditionally been a decentralized process, and states have determined voter requirements and when ballots must be returned.

It is already illegal for noncitizens to vote in the U.S.

“Documented studies from organizations on the Right and the Left have shown that voter citizenship fraud is a vanishingly rare issue,” Levine said.

Voters who try to claim they are citizens when they are not are actually creating a paper trail that could lead them to face criminal penalties, he explained.

“Voter citizenship fraud is very rare,” Levine said. “That doesn’t mean there can’t be laws put in place to try and deal with that, but that is the jurisdiction of Congress and no one else.”