The Democratic Party of Hawaii has appealed a federal judge's ruling in November that upheld the state's open primary system as constitutional.
The party has argued that allowing all voters to participate in the party's primaries is a violation of the First Amendment right to free association.
U.S. District Judge J. Michael Seabright ruled that the party failed to show that the open primary system places a "severe burden" on its First Amendment rights -- the legal standard for courts when reviewing election law challenges -- and also failed to present evidence documenting the harm to the party.
David Sgan, an attorney representing the party, filed the notice of appeal on Thursday. The appeal will be heard by the 9th U.S. Circuit Court of Appeals.