AUGUSTA — A bipartisan bill that would allow Maine’s Indigenous tribes to benefit from more federal laws won the endorsement of a legislative committee in a 10-4 vote Thursday.

But opposition from a top adviser to Gov. Janet Mills suggests that the bill faces a likely veto if it is passed by the full House and Senate. Gerald Reid, Mills’ legal counsel, said the proposal raises so many legal questions about the overriding of unspecified state laws that it is “unconstitutionally vague.”

Spokespeople for Mills did not respond Thursday afternoon to questions about her stance on the legislation. Sen. Anne Carney, D-Cape Elizabeth, who co-chairs the Judiciary Committee, expects that the bill’s supporters will attempt to override a veto should the governor issue one.

L.D. 2004, sponsored by House Speaker Rachel Talbot-Ross, D-Portland, and co-sponsored by six Republicans, including House Minority Leader Billy Bob Faulkingham, of Winter Harbor, would allow Maine’s tribes to join the nation’s 570 other federally recognized tribes in benefitting from most existing and future federal laws. A notable exception is federal gambling laws, where the bill prioritizes state jurisdiction.

Maine’s four tribes were excluded from automatically receiving these benefits as a result of the 1980 Maine Indian Claims Settlement Act, an agreement between the state and the tribes that gives the state jurisdiction. The agreement also states that federal Indian laws undermining that jurisdiction would not apply to Maine’s Indigenous communities without specific permission from Congress.

The bill to overturn that part of the settlement act was amended by the Judiciary Committee Thursday in hopes of swaying the governor and other critics. The amended version attempts to carve out certain state laws the tribes still would have to follow – such as those governing environmental regulations – so that they would not be overridden by federal law.

The amendment did not satisfy opponents, who said the catch-all approach taken by the bill, even with the effort to carve out some state laws, would create unforeseen legal conflicts and that the bill is too complex and far-reaching to take up in the waning days of the legislative session.

Some committee members said they wished they had more time to consider the bill and urged for it to be revisited at a later time. It was not presented until two weeks ago and the session is scheduled to end Wednesday.

But for some supporters, advancing the bill was an expression of solidarity with the tribes.

Rep. Lois Galgay Reckitt, D-South Portland, was skeptical of the bill’s ability to pass through the House and Senate given the opposition, but emphasized she would be voting in favor to get its objectives on the Legislature’s radar before the end of session. She pointed out that she and other lawmakers have been trying to expand tribal rights for years.

“It’s my seventh year on this issue and I’m tired of not getting anywhere,” she said.

Reid, Mills’ legal adviser, said the bill’s approach of allowing Maine tribes to benefit from all federal statutes by default is unworkable, and that federal statutes should be implemented on a case-by-case basis so that the legal impacts are clear. Passing a sweeping state law without understanding how it will affect existing state laws is “unconstitutionally vague” because “it deprives ordinary citizens of knowing what the law is.”

He also said certain areas of the amended bill that are supposed to act as carve-outs to limit future legal conflicts would not resolve the jurisdictional issues created by the bill.

According to tribal leaders, the settlement act’s requirement of congressional approval for Maine tribes to benefit from federal tribal legislation was never consented to by the tribes before passage. The claim has been the basis of the tribes’ years-long effort to gain access to the legislative protections enjoyed by other tribes nationwide.

That narrative is disputed in a letter to the Judiciary Committee from John M.R. Paterson, who represented the state in negotiations between the tribes and the federal government that resulted in the enactment of settlement act. Paterson says the provision of the agreement was consented to by the tribes and that no one from the original tribal negotiation team, nor their lawyers, has ever claimed to have been unaware of the agreement’s language.

The committee vote Thursday came a day after unanimous House and Senate votes to support L.D. 78, a bill that would require the state to resume printing treaty obligations to Native Americans in the Maine Constitution. In written testimony, Reid claimed the obligations have never been in dispute and that the bill “appears to be a misguided attempt to right a historical wrong that never occurred.”