The Supreme Court is wrestling with a case that could make sports betting widely available.

The case heard Monday is a result of New Jersey's yearslong effort to bring sports betting to its casinos and racetracks. The case pits New Jersey and other states against all four major U.S. professional sports leagues, the NCAA and the federal government.

New Jersey is challenging a federal law that bars states from authorizing sports gambling. The law has exceptions for Nevada, Montana, Oregon and Delaware, which had approved some form of sports wagering before the law took effect.

The justices could ultimately greenlight the expansion of sports gambling nationwide by striking down the federal law.

New Jersey Gov. Chris Christie says that if the Supreme Court rules in his state's favor in a major sports betting case, then sports betting would quickly become available in the state.

The Republican governor was in Washington on Monday to hear arguments in the case. Christie said outside court that if the justices rule in New Jersey's favor, "we could have bets being taken in New Jersey within two weeks of a decision by the court."

The American Gaming Association estimates that Americans illegally wager about $150 billion on sports each year.

It released this statement: 

“Today is a positive day for the millions of Americans seeking to legally wager on sporting events. While we can’t predict the intentions of Supreme Court Justices, we can accurately predict the demise of the Professional and Amateur Sports Protection of 1992 (PASPA). The justices of the Court expressed deep interest in the role of the federal government - a role that we believe has created a thriving illegal market that has driven trillions of dollars to offshore websites and corner bookies. States and tribal sovereign nations have proven to be effective regulators of gaming and today’s oral arguments before the Supreme Court moved them one giant step closer to offering a new product that Americans demand.”

(The Associated Press contributed to this report.)