A federal appeals court has upheld a ruling halting President Donald Trump’s executive order aimed at creating a federal list of eligible voters and restricting mail ballot delivery. This decision affects nearly half of the U.S. states.

The ruling, issued by judges of the 1st U.S. Circuit Court of Appeals, rejected the administration’s attempt to move forward with these mail-in voting restrictions in 23 states that filed lawsuits prior to the November midterm elections.

Trump’s executive order, announced in March, instructed the director of U.S. Citizenship and Immigration Services and the commissioner of the Social Security Administration to develop a “state citizenship list” for eligible voters. It also mandated the U.S. Postal Service to deliver mail ballots solely to individuals on this list.

Trump promoted the changes as necessary measures to prevent non-citizens from voting. However, state election officials expressed concerns over possible abuse and election disruption. Democratic representatives from 23 states and the District of Columbia challenged the order in U.S. District Court in Boston, arguing it was unconstitutional because election rules are determined by the states and Congress, not the president.

U.S. District Court Judge Indira Talwani, appointed by Democratic President Barack Obama, agreed with the challengers and blocked the implementation of the order for the November elections, but only for the states involved in the lawsuit.

The Justice Department responded in an emailed statement saying it is “reviewing all options” for future legal actions, expressing confidence that Trump’s executive order will eventually be upheld.

Reporter Bynum covered the story from Savannah, Georgia.