Before the end of this year, Russell and Sallie Nordyke will set up shop for at least five gun shows at the Santa Clara County fairgrounds, providing a gathering spot for thousands of gun enthusiasts to buy and sell rifles, pistols and other weapons.

For the Glenn County couple, the South Bay is a small island amid a sea of hostility toward their TS Gun Shows. Bay Area counties from Alameda and Marin to San Mateo have enacted laws that forbid the sale or possession of guns on government property, effectively banning gun shows at some of the best spots to hold them.

The Nordykes believe those laws are unconstitutional — and on Monday, a federal appeals court will once again take up their 12-year quest to strike down the regulations.

The case offers another crucial test of Second Amendment rights that could have repercussions for California’s sweeping slate of state and local gun control laws.

Specifically, an 11-judge 9th U.S. Circuit Court of Appeals panel is to hear arguments in the Nordykes’ legal challenge to Alameda County’s ordinance, which has outlawed gun shows at the fairgrounds in Pleasanton since 1999.

“It has impacted our lives tremendously,” Sallie Nordyke said. “We used to be able to have gun shows in a lot of other places.”

With gun rights groups such as the National Rifle Association on one side and gun control advocates such as the Brady Center to Prevent Gun Violence on the other, the Nordyke case is being closely watched across the country. The showdown is considered a barometer of how far local and state governments can go in regulating guns following U.S. Supreme Court rulings expanding constitutional protections for the right to bear arms.

The most recent of those rulings, in a Chicago case two years ago, established that the Second Amendment applies to state and local gun control regulations. But it left unresolved the legal survival threshold for laws such as Alameda County’s, and the 9th Circuit is expected to tackle that issue in the Nordyke case.

The outcome could determine the fate of gun show regulations in California and other states within the 9th Circuit and may also shape ongoing legal challenges to other gun controls. With the Nordyke case pending, the 9th Circuit has put on hold two cases challenging California’s strict limits on carrying concealed weapons and licenses for carrying loaded firearms in public.

“This could be the next big gun case to go to the Supreme Court,” said Adam Winkler, a UCLA law professor and author of “Gunfight: The Battle Over the Right to Bear Arms in America.” “It does pose a big question: whether the right to bear arms extends outside the home.”

Winkler cautioned, however: “The gun show promoters have an uphill climb. When managing its own property, the government usually has a lot of (leeway).”

In fact, a three-judge 9th Circuit panel in 2009 upheld the county’s law, finding it a “reasonable” form of regulation, but the court decided to reconsider the case with an 11-judge panel in the aftermath of the Supreme Court’s major gun rights rulings.

The Nordykes have a history of pressing their cause, winning a case against Santa Clara County in the late 1990s when a federal judge concluded a gun show ban ran afoul of their free speech rights. With no regulation in place, the Nordykes have been able to hold gun shows in Santa Clara, including one this past weekend.

But Alameda County crafted its law to avoid Santa Clara County’s legal problems, using language other counties have borrowed. Spurred by former Supervisor Mary King, Alameda County outlawed firearms on county property in response to concerns about a spate of gun-related violence across the East Bay at the time.

The Nordykes and gun rights advocates say there is no connection between gun violence and gun shows, arguing the Alameda County law arbitrarily targets the “gun culture.” They maintain the ordinance undercuts Second Amendment rights, as well as their First Amendment rights to gather on public property for a gun show. Most legal experts say the 9th Circuit is primarily focused on the gun rights issue.

“The ordinance singles out Second Amendment activity for disfavored treatment and declares county property a Second Amendment-free zone,” former U.S. Solicitor General Paul Clement wrote in a 9th Circuit brief on the NRA’s behalf.

Alameda County’s lawyers did not respond to requests for comment but have previously said the gun ban on government property is just the type of regulation the Supreme Court suggested would withstand a legal challenge. In court papers, they urged the 9th Circuit to uphold the law, saying there are “ample alternatives” for gun show promoters to hold events on private property.

The Nordykes are certainly ready to get the issue resolved.

“It has just gotten bigger and bigger and bigger,” Sallie Nordyke said. “I never dreamed it would go on this long. I know more about the court system than I ever wanted to know.”

Howard Mintz covers legal affairs. Contact him at 408-286-0236 or follow him at Twitter.com/hmintz.