The Wampanoag Tribe of Gay Head (Aquinnah) has new leverage in its plans to build a gambling hall on Martha’s Vineyard and is signaling a readiness to lobby for a more lucrative prize — a casino on the mainland.

On Monday, the tribe won a substantial legal victory when the US Supreme Court declined to hear a case challenging the proposed slot parlor, leaving in place a lower court decision that appears to let the project move forward.

The federally recognized tribe wants to build a small casino with several hundred machines on sovereign land on the western end of the island, as permitted by federal law. Vineyard officials and residents have fought hard against the plans, saying a casino would change the character of the beloved summer resort and occasional presidential retreat.

“Now that this issue is finally resolved, we’d like to put the legal battles behind us, and focus on working with the town and Commonwealth; to weigh our options and determine the best pathway forward for us to provide the necessary services of health care, elders’ and children’s services, education, housing, and employment opportunities for all of our tribal members,’’ the tribe’s chairwoman, Cheryl Andrews-Maltais, said in a statement.

From the tribe’s point of view, the best path forward could be a mainland casino in Southeastern Massachusetts, which would bring in far more business than a small facility on the island.

“If the Vineyard is the only alternative, they’ll build on the Vineyard,’’ said a person close to the tribe and familiar with its thinking. “If there is another alternative, they’ll build there.’’

The person spoke on the condition of anonymity because the person is not authorized to speak on the tribe’s behalf.

The tribe has long harbored aspirations for a casino on the mainland, dating back to at least the administration of Governor William Weld in the 1990s.

In 1995, Weld struck a deal with the tribe to build a casino in New Bedford, but the plans fizzled.

“A mainland casino has long been their end game,’’ said Clyde Barrow, a University of Texas professor who has studied the New England gambling industry.

In 2012, the Aquinnah tribe proposed a casino in Freetown and Lakeville, but residents opposed the idea in a pair of nonbinding votes.

Striking a deal with state officials for a mainland casino would not be easy, and would probably require amending the state’s 2011 casino law, Barrow said.

“If they were to go down that road, it’s another decade away, in my view,’’ Barrow said. “It’s way down the road, and a lot of politics.’’

Barrow said he has seen no appetite among lawmakers to expand gambling in Massachusetts, especially with the state’s resort casinos — Wynn Resorts in Everett and MGM in Springfield — still under construction.

“People want to see what happens with Springfield and Wynn,’’ he said.

The more likely outcome is that the tribe eventually builds on its Vineyard reservation, Barrow said, despite its limitations.

“From a marketing standpoint’’ a remote spot on a summer resort island “is just a horrible location for a casino,’’ he said.

“You don’t go to Martha’s Vineyard to play slot machines,’’ he added.

On the other hand, most tribal casinos in the United States are small facilities with a few hundred slots, he said. These facilities can still turn a decent profit for a tribe looking to expand services to its members.

Barrow estimated that a tribal slot parlor on the Vineyard would earn about $3 million a year, or perhaps a bit more.

Casino specialist Paul DeBole, a Lasell College political scientist, said the Vineyard casino would not be taxed by the state. That could potentially allow the tribe to compete with commercial casinos by paying out more in winnings.

Governor Charlie Baker’s office did not address the prospect of discussions with the tribe, but in a statement pledged it would “continue to closely monitor any developments.’’

Andrews-Maltais was out of state Tuesday and not available, her office said.

The Massachusetts Gaming Commission, which regulates commercial casinos in the state, said it “does not currently have any statutory role or authority over the matter involving the Town of Aquinnah and the Wampanoag Tribe of Gay Head.’’

Still, the commission said that it will keep an eye on the developing situation with the tribe. The state’s other federally recognized tribe, the Mashpee Wampanoag, has been trying for several years to build a tribal casino in Taunton, but its plans have been tied up in court.

Mark Arsenault can be reached at mark.arsenault@globe.com. Follow him on Twitter @bostonglobemark