The Arizona state government has told the U.S. Supreme Court that it won’t file a response in Arizona Libertarian Party v Bennett, 15-598. This is the case in which the Libertarian and Green Parties are fighting the law that says only the two largest parties should have their own checkbox on the voter registration form. The Libertarian and Green Parties are also on the Arizona ballot and they nominate by primary, just as the Democratic and Republican Parties do.
The Arizona law is especially harmful to the Green Party, because it never has enough registered members to remain ballot-qualified. Chances are, if the Arizona form mentioned the Green Party as a registration choice, after a few years Green registration would rise high enough so that it would remain on the ballot.
If the Supreme Court asks Arizona to respond, then Arizona will respond. The Court hasn’t yet set a conference date for this case.