In a state that's home to a university whose mascot is a gamecock, a group of South Carolinians arrested in a major cockfighting case want an appeals court to throw out their federal convictions. They argue that the federal government has no business regulating bird fights within state borders.

In a case closely watched by animal-rights activists, a three-judge U.S. appeals court in Richmond, Va., on Tuesday heard arguments on whether federal prosecutors overstepped their authority in trying six people in connection with Lexington County cockfights in 2008.

The four men and two women were found guilty at a federal court trial in May 2010 of violating animal welfare laws  -- the same laws that were used to prosecute star NFL quarterback Michael Vick and send him to federal prison in 2007 for organizing dogfights at his Virginia home.

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During the South Carolina trial, prosecutors showed video secretly shot by a state Department of Natural Resources agent who went undercover to infiltrate the cockfights at an arena in the rural Lexington County town of Swansea.

The federal government brought in witnesses from out of state -- and even flew in one witness from England -- to prove their case that the defendants were involved in interstate commerce -- which would give the federal government jurisdiction.

The six are appealing their convictions, and the outcome could also affect several others who pleaded guilty and didn’t go to trial.

Rauch Wise, an attorney for the defendants, says the federal government should not be in the business of regulating what essentially is a state matter.

In South Carolina, cockfighting is a misdemeanor punishable by up to a year in jail, though many violators often get off with a fine. Under the federal law, violators face up to five years in prison, Wise noted.

The defendants got sentences ranging from three years probation to 21 months in prison.

“Congress does not have right to prohibit burglary simply because someone steals a TV that was made out of state,” Wise told msnbc.com in a telephone interview Tuesday after arguing the case before the appellate panel. “Those are state matters reserved to the state and should be handled by state.

“They’ve taken laws in various states that citizens in those states have passed and in essence are saying, ‘you’re not being tough enough.’”

In an accompanying court filing, Wise argued the case did not involve interstate commerce. "Under the theory used by the Government in this case, Congress would have the power to make littering in a state a (federal) crime."

Nathan Williams, the assistant U.S. attorney who argued for the government, said the federal law prohibiting animal fighting was a proper exercise of congressional power under the Interstate Commerce Clause.

In court documents, the government outlines several reasons why the case involved “interstate commerce.” Prosecutors noted that several items, including leg bands, call slips for recordkeeping, vitamins, a syringe and a scale, were shipped from outside South Carolina to people present at the cockfights.

Citing a previous ruling in another animal-fighting case, Williams argued:

“Whether or not the knives, gaffs or other instrumentalities themselves substantially affect interstate commerce is not the relevant question. The fact that these instruments are used in an animal fighting venture that affects interstate commerce is sufficient to permit Congress to criminalize the selling, buying, transporting or delivering of them pursuant to its power under the Commerce Clause.”

Cockfighting is a centuries-old blood sport in which two or more specially bred roosters are placed in an enclosed pit to fight, often to the death. The University of South Carolina’s men’s sports teams have traditionally been called the Fighting Gamecocks.

• Watch Humane Society of the United States video on cockfighting in South Carolina

The Humane Society of the United States is trying to make cockfighting a felony in all 50 states. John Goodwin, director of animal cruelty policy for the organization, who attended the appeals hearing, says it’s clear that the South Carolina case stretched beyond state borders.

“This is not just a matter of two chickens pecking each other in the back of some farmyard. These are large-scale events that affect interstate commerce in a pretty significant way,” he told msnbc.com

Goodwin said there have been about a dozen prosecutions under the federal Animal Welfare Act in the past seven or eight years, at least half of which involved cockfighting. He couldn’t recall any previous cases that reached a federal appeals court.

“Hopefully he judges will agree that the  law that was used to prosecute Michal Vick is a good law that would stand,” Goodwin said.

Wise said he expects a ruling from the appellate panel within 90 days.

“The significance of this case is what limit there is on the power of Congress to essentially regulate what is a state matter, cockfighting,” he said.

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