The Arizona Libertarian Party is fighting a state law that it says is designed to keep Libertarians off the ballot.

They’re now arguing their case before the U.S. Supreme Court.

In 2015, the Arizona Legislature passed a law that required parties to include independents when calculating the number of signatures required to get on the ballot. This, in effect, forced Libertarians to collect signatures from 10% of their base, compared to less than half a percent for Republicans and Democrats.

Arizona’s House speaker at the time, Republican J.D. Mesnard, pushed for the change, saying Libertarian candidates were siphoning votes from Republicans — costing the GOP at least two seats in Congress.

No Libertarians made it to the ballot in 2018.

The 9th Circuit Court of Appeals upheld the law in a ruling earlier this year.