PHOENIX — A Republican challenger for state attorney general is using the issue of prayer at public meetings to raise money for his campaign.

Mark Brnovich is accusing incumbent Tom Horne of refusing to add his voice to arguments before the U.S. Supreme Court that there is a constitutional right to have prayers at events like city council meetings. What’s at stake, he said, is whether the high court will erode religious liberty at the behest of “groups like the ACLU.”

“Join us today in support of religious liberties,” Brnovich told those who he hopes will donate money “to help us spread our message and protect public prayer!”

Horne countered that he did sign on to a legal brief, filed by Indiana Attorney General Gregory Zoeller, urging the high court to review that lower court ruling.

But Brnovich argued that brief simply asked the justices to intercede to provide clarity so governments know what is and is not allowed. He said Horne did not sign on to a subsequent legal brief, also prepared by Indiana, which had a more detailed defense of prayer at public meetings.

Horne said these kinds of multistate briefs are traditionally handled by one or two attorneys general and others are asked to sign on. Horne said he cannot explain why he is not on the second brief but said he never “refused,” as Brnovich is accusing, saying it may simply be that he was not asked or something fell through the cracks.

And Horne insisted he does support prayer at public meetings, something he said is reflected in that first legal brief he signed. Horne called the accusation, made in a Brnovich fundraising email, an attempt to get noticed.

“No one’s paying attention to him,” Horne said.

Hanging in the balance — beyond who is the GOP nominee for state attorney general — is the legality of prayers that regularly begin the sessions of the Arizona Legislature along with many city council, county supervisor and school board meetings.

It was presumed the issue was settled when the high court ruled in 1983 that prayer before public meetings is “part of the fabric of our society.” The justices said nothing about such prayers ran afoul of constitutional provisions barring the state from establishing a religion.

But federal appellate judges ruled last year that the practices of the town of Greece “must be viewed as an endorsement of a particular religious viewpoint” and therefore unconstitutional. The judges said they reached that conclusion based on the process for selecting who gives the prayers and the content of what is actually prayed, all of which “virtually ensured” that “a Christian viewpoint” would be represented.

Foes of the appellate court ruling said its big flaw is that it essentially puts courts in the position of analyzing specific prayers and second-guessing whether the content crosses some line.

The Supreme Court heard arguments earlier this week from those directly involved. .

Horne is trying to beat back a challenge by Brnovich, a former state gaming director, to again become the Republican candidate in 2014. At this point, the only Democrat in the race is Felecia Rotellini, who lost narrowly to Horne in 2010.