The U.S. Supreme Court has agreed to hear an appeal in New Jersey’s long-running effort to legalize gambling on sports events.

In the case, the justices are expected to consider whether the federal Professional and Amateur Sports Protection Act, which has been held to bar New Jersey’s sports-gambling scheme, violates the Tenth Amendment.

A win at the Supreme Court would be especially sweet for Gov. Chris Christie, who has long advocated legalized sports betting but has faced numerous roadblocks. Christie backed a 2011 nonbinding referendum to allow sports gambling that the electorate passed by a two-thirds vote. But the referendum was followed by a lengthy litigation phase as the National College Athletic Association and professional football, baseball, basketball and hockey leagues fought the plans for legalized wagering. The latest setback for sports wagering proponents was an August 2016 ruling by a 12-member panel of the U.S. Court of Appeals for the Third Circuit, which held that PASPA is not an unconstitutional restriction on the power of the states.

The Supreme Court granted certiorari in two cases, Christie v. NCAA and NJ Thoroughbred Horsemen v. NCAAafter New Jersey urged the court to restore the “carefully-calibrated” balance between state and federal power “that the Third Circuit’s decision has so thoroughly upended.” New Jersey said in its petition that the Third Circuit ruling is “not a minor intrusion on state sovereignty” but “a sea change to our system of federalism.”

In an unusual move, the Supreme Court sought input from the U.S. Solicitor General’s Office before deciding whether to hear the New Jersey cases. The solicitor general’s office responded in May with a 24-page brief urging the court not to grant certiorari in the New Jersey case, and arguing that PASPA does not violate the Tenth Amendment because it neither compels states to regulate according to federal standards nor requires state officials to administer federal law. PASPA prohibits states from running sports-gambling schemes or authorizing private parties to do so, which are a permissible exercise of Congress’ authority to regulate state activities and pre-empt state laws, the solicitor general’s office said in its brief.

The current case arose over a law that was enacted in 2012 and revised in 2014, which allowed gambling on certain professional, college and amateur sports by people over age 21. Sports betting would be limited to casinos and racetracks as the plan is aimed at the economic revitalization of those businesses. Wagering on sporting events taking place in New Jersey or events in which any New Jersey college team participates would be excluded under the law.

The case accepted by the high court is the second challenge brought by sports leagues to the New Jersey law authorizing sports gambling. The first suit involved a 2012 statute that was held by the Third Circuit to be invalid under PASPA. The Supreme Court declined to grant certiorari in that case.

PASPA, enacted in 1992, outlawed most forms of sports betting nationwide, with the exclusion of Oregon, Delaware, Montana and Nevada, which had legalized some forms of betting at the time the law was enacted.

The second case was an apparently more compelling pick for the court because the constitutional issues were more acute than in Christie I, said Daniel Wallach, an attorney at Becker & Poliakoff in Fort Lauderdale, Florida, who blogs on sports gambling law and handles sports gambling cases. Christie II provides an opportunity for the court’s conservative wing to address the proper balance between federal and state sovereignty, said Wallach.

“If a federal government can dictate how a state regulates its own citizens, it presents a more pernicious violation of state sovereignty,” Wallach said.

This year might have been the right time to press the issue of whether to legalize sports gambling, since the court’s docket was unusually light when it took the Christie II case, said Wallach.

“I think if the court is inclined enough to grant certiorari, it’s going to give this a long, hard look,” said Wallach. “If four judges took an interest in this, I think it’s a strong indicator that PASPA’s days might well be numbered,” he said.

Wallach said the court’s decision to take the Christie II case might stir up momentum for creation of federal legislation to allow sports wagering.

“There’s a 100 percent likelihood sports gambling will become legal. The question is when, or how,” Wallach said.

Christie, at a press conference Tuesday, said, “I’m thrilled that we got certiorari at the Supreme Court. Very few cases get granted certiorari by the Supreme Court, so I’m very optimistic and looking forward to having conversations later today with Ted Olson, who represents us on the Supreme Court. And I don’t know, I’m feeling pretty good he’s got a .750 winning percentage in the Supreme Court, so I feel pretty good having Ted Olson represent us. So you know, again, if the Supreme Court goes the other way I don’t know what our options are, but we’ll have to make that evaluation at the time. But the fact that the Supreme Court granted cert in this case is a very good sign for sports betting having a future in New Jersey. I’m encouraged by it. We’re not declaring victory, but at least we’re in the game and that’s what we want to be.”

Olson of Gibson, Dunn & Crutcher in Washington, a former U.S. solicitor general, represented New Jersey on its certiorari petition. He did not respond to a reporter’s call about the case. Paul Clement of Kirkland & Ellis in Washington, another former U.S. solicitor general, represented the sports leagues in their position opposing certiorari. He did not return a call, but another lawyer for the sports leagues, Jeffrey Mishkin of Skadden, Arps, Slate, Meagher & Flom in New York, declined to comment. A spokesman for MLB declined to comment. Representatives of other sports leagues did not return calls.