A federal lawsuit challenging a state law to allow sports betting just got even more crowded.

In two separate motions filed with the U.S. District Court in Trenton on Wednesday, State Senate President Stephen Sweeney, Speaker of the House Sheila Oliver and the New Jersey Thoroughbred Horsemen’s Association asked to be made a party to the lawsuit, arguing they have a stake in the outcome.

All three said they have a stake in the issue, with Sweeney and Oliver arguing the two legislative bodies they represent passed the New Jersey Sports Wagering Law and want to protect their law-making authority, alongside Gov. Chris Christie.

“The presiding officers have a significant interest in protecting the legislature’s authority under the New Jersey Constitution to determine how best to raise and appropriate revenue for the benefit of its citizens, and how best to regulate gambling at any particular time,” lawyers from the Newark-based Gibbons firm argued on behalf of Sweeney and Oliver in the brief.

“Absent intervention, that interest could be impaired by the disposition of this case and may not be adequately represented by the existing defendants, all of whom are officers of the executive branch,” according to the brief.

Earlier this year, the National Collegiate Athletic Association, National Basketball Association, National Football League, National Hockey League and Office of Commissioner of Baseball filed the suit against Christie and regulators, challenging a state law permitting the Division of Gaming Enforcement to regulate sports betting.

Sports wagering is illegal in every state except the four -- Nevada, Delaware, Oregon and Montana -- that allowed some form of betting prior to the passage of the federal Professional and Amateur Sports Protection Act in 1992.

The state has argued the leagues and sports organizations lack standing to sue because they cannot prove wagering on sporting events would financially harm the organizations.

In light of recent court decisions siding with the state requiring that the lawsuit proceed without delay, the decision for legislators to get involved may reflect a certain confidence on their part, according to some observers.

“This may be a move to politicize the process,” said Michael McCann, a sports law professor at the University of Vermont. “Some are confident they’re going to win. But of course, it’s very early and the state has to overcome the legal argument.”

The horsemen’s association, which operates Monmouth Park, also wants to intervene in the lawsuit, arguing it has a stake in the matter because it wants to implement sports wagering in New Jersey. The association’s more than 3,000 members would be harmed if the leagues were successful in convincing the court to issue an injunction prohibiting sports wagering.

“Any injunction against the NJTHA will likely sound the death knell for Monmouth Park and the thoroughbred horse industry in New Jersey,” the association’s lawyer, Morristown-based Ronald J. Riccio, wrote in a letter to the court. “The NJTHA believes that sports betting is an essential component of the NJTHA’s overall plan to make Monmouth Park an economically self-sustaining thoroughbred racetrack.”

The association, Sweeney and Oliver are asking to make their arguments in person on Dec. 17, one day before the governor and sports leagues also are expected to appear in court in the matter.

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