In a historic vote that could vastly increase their membership, White Earth Band of Ojibwe members have overwhelmingly approved a new constitution.

The new document removes a requirement that tribal citizens possess one-quarter Minnesota Chippewa Tribe blood, a controversial "blood quantum" standard adopted at the urging of the federal government decades ago. Under the new constitution, White Earth's declining citizenship will instead be based on lineal descent.

The change could mean more than doubling the population, which now stands at under 20,000.

According to ballots counted Tuesday night, nearly 80 percent of the nearly 3,500 votes cast approved of adopting a new constitution, which in addition to changing citizenship standards will create a tribal government with three branches and a separation of powers instead of one tribal council overseeing everything.

The old citizenship standard was divisive among families, with some members having children or grandchildren who couldn't become citizens, said Jill Doerfler, associate professor of American Indian studies at the University of Minnesota Duluth. Lineage citizenship won't be automatic, however. People will still need to apply to become citizens, said Doerfler, who consulted with the tribe on reforming the constitution.

The move is contrary to many American Indian tribes, which want to cap the number of members, concerned about distributing limited gaming profits and using up natural resources.

"There's a number of people who make … a substantial percentage of their basic livelihood off the land" and opposed the new constitution's membership definition, said Terry Janis, a Pine Ridge tribal member who was hired as White Earth's constitutional reform project manager. Others opposed the change because they were concerned about more people taxing already-scarce financial resources and changing the nature of what it means to be a White Earth member.

White Earth does not distribute per-capita payments to its members. New members may be eligible for some government programs that they couldn't use before, Doerfler said, though the one-quarter quantum blood requirement in some federal programs won't change.

Janis said some scholarships and services offered by federal, state and private resources require only tribal membership without defining a blood level, so new members may benefit from those.

Also, he said, "there's a sense of belonging to being … an enrolled member of a tribe."

The new constitution could take a year or two to implement. White Earth is the first tribe in Minnesota to discard its governance structure and start over, Janis said. Outside observers say it's an unusual move nationwide.

A study projected that, under the quantum blood requirement, membership numbers would have fallen drastically in the future.

"The reality is that people marry who they marry and love who they love," said Matthew L.M. Fletcher, a law professor and director of the Indigenous Law & Policy Center at Michigan State University. White Earth, he said, recognizes the "pragmatic reality … that if they didn't change their membership criteria, a few decades down the road they're going to start seeing a severe drop-off … you can't have a tribe without people."

White Earth leaders have said a new constitution could also be the key to attracting new businesses, running clean elections, creating an impartial judiciary and creating a place where more people want to live, work and invest.

"Business is definitely a very tangible reason, but I suspect that it's broader than that," Fletcher said. "This is one of the ways to correct the possibility of having a long-term leader who has a lot of power."

Doerfler grew up on White Earth but is not a member because of the blood rule. A larger population will give White Earth more political clout, she pointed out.

"Blood quantum is designed to erase and eliminate native people's political status," she said.

The new document supplants the constitution that the band has been living under as one of six member nations of the Minnesota Chippewa Tribe.

The vote didn't clarify what White Earth's relationship will be with the other five member nations in the future. Janis said White Earth leaders are committed to negotiating a way to remain part of the larger organization.