By BOB CHRISTIE, Associated Press

PHOENIX (AP) — A federal judge on Monday upheld the constitutionality of a state law that the Libertarian Party contends was designed to keep its candidates off Arizona ballots.

The ruling by U.S. District Judge David Campbell rejected arguments from the Libertarian Party that the law increasing the number of qualifying signatures party candidates need violates their constitutional rights.

The law backed by Republicans was enacted in 2015 and has had a major impact. Only one Libertarian seeking to run for the state Legislature or Congress made the ballot in 2016. In 2014, 18 Libertarian Party members were on the ballot.

"When we typically had anywhere from 18 to 30 candidate across the board in Arizona, we have one," said Michael Kielsky a former chairman of the state party. "So it absolutely caused a significant impact."

The signature requirements to get on the primary ballot for a statewide office increased from as little as 133 for a Libertarian Party candidate to more than 3,000. The party only has about 32,000 members in Arizona, while there are nearly 1.3 million Republicans.

The 2015 law revived part of a 2013 law that was repealed after voters collected enough signatures to get it on the ballot. The bill by current House speaker J.D. Mesnard passed with no Democratic support.

During debate on the 2013 bill, Mesnard acknowledged the reason for pushing the signature change that would make it harder for Libertarians to get on the ballot.

"I believe that if you look at the last election there was at least one, probably two congressional seats that may have gone a different direction, the direction I would have liked to have seen them go, if this requirement had been in place," Mesnard said during the debate.

Kielsky said Republicans created a law "laser-focused" on his party because they believed Libertarians were draining votes from GOP candidates. He said an appeal is likely and that the ballot qualification requirements for the two parties are out of balance.

Campbell wrote that while there might be an imbalance, it's not so skewed that it violated the rights of Libertarian voters or guidelines laid out by the U.S. Supreme Court.