The Wabanaki Nations are jumping into the legal fray over Maine’s internet gambling law.

The Oxford Casino sued the state in January, contending that the new law granting tribal nations the exclusive right to operate online casino games was an illegal “race-based monopoly.”

All four Wabanaki tribes — the Houlton Band of Maliseet Indians, the Mi’kmaq Nation, the Passamaquoddy Tribe and the Penobscot Nation — filed a joint motion to intervene in the lawsuit Wednesday evening. A judge granted their request Thursday.

Gov. Janet Mills allowed the bill to become law without her signature on Jan. 8, giving in to the tribes’ lobbying despite her lingering hesitations and the opposition of several state agencies.

The Oxford Casino, one of the two brick-and-mortar locations that offer table games in Maine, has long opposed opening the marketplace to online gambling. But if Maine is to become the eighth state to legalize iGaming, the casino and its owners, Kentucky-based Churchill Downs Inc., are demanding a piece of the pie.

The tribes’ concerns are economic, first and foremost. But the suit could also threaten the legal foundation underlying tribal sovereignty.

Wabanaki governments deliver an extensive slate of services to tribal and nontribal citizens alike. Among them are health care, food assistance, employment opportunities, domestic violence and sexual assault services, and improvements to public infrastructure, chiefs told the court.

They do these things without some of the benefits conferred upon the other 571 federally recognized tribes nationwide due to the unique legal framework of the 1980 Maine Indian Land Claims Settlement Act.

Notably, the Wabanaki Nations have not historically been allowed to enter the gambling economy because the Indian Gaming Regulatory Act, a 1988 federal law granting the right to tribes to operate casinos on tribal land, does not apply in Maine.

Tribal leaders have made compelling economic arguments and successfully cracked open access to the gambling market, first through the 2023 law that gave them exclusive access to online sports betting, and then again this year.

“This law is crucial to advancing the Houlton Band’s efforts to develop independent, long-term revenue sources that are not dependent on federal funding and will enable us to support and expand governmental services for Maliseet families and other community members,” Houlton Band Chief Clarissa Sabattis said in her declaration to the court.

Oxford argues that the state sanctioned a “race-based monopoly” on iGaming, and in doing so violated the Equal Protection Clauses of both the United States and Maine constitutions, which prohibit discrimination based on race.

That argument, tribal attorneys say, “directly target the Nations’ unique constitutional and political status.”

Courts have long held privileges extended to tribal members or nations are not made on the basis of race, but on the basis that tribes are sovereign political entities.

“Adopting Plaintiffs’ equal protection theories could threaten the validity of countless laws that classify based on the unique sovereign status of federally recognized tribes,” attorneys state in their filing.

“This attack represents an unfortunate effort to undermine Tribal-state partnership. It seeks to undermine the legal basis for constructive government-to-government policy collaboration, despite decades of data showing that tribal and nontribal communities alike are stronger when Tribal nations are empowered in their pursuit of self-determination,” said Lenny Powell, an attorney for the Native American Rights Fund representing the Wabanaki Nations.

Reuben M. Schafir is a Report for America corps member who writes about Indigenous communities for the Portland Press Herald.