WASHINGTON -- The estimated 1.5 million American Indian voters nationwide is a tiny fraction of the more than 100 million U.S. registered voters, but the concentration of American Indians in three states with Democratic presidential contests on Tuesday -- Arizona, New Mexico, and Oklahoma -- gives them a chance to demonstrate their growing political clout.

Recognizing the opportunity to both showcase and boost their political strength this year, tribal leaders recently launched "Native Vote 2004'' in an effort to persuade more American Indians to vote while keeping them apprised of the latest campaign developments. The National Congress of American Indians has pledged to mobilize one million American Indian voters this fall in eight states with significant American Indian populations: Alaska, Arizona, California, Michigan, Minnesota, New Mexico, Oklahoma and South Dakota.

While American Indians traditionally have tended to vote for Democratic candidates, that is changing. Support for candidates generally tends to be more "issue based'' than partisan, said national congress Executive Director Jacqueline Johnson. "Although we still have a strong Democratic voice in Indian Country, there is a growing Republican constituency."

Politicians of both parties have readily responded to the burgeoning political power of American Indian voters, as well as the increasingly large campaign contributions from tribes newly enriched by casino and gaming receipts.

In November, six of the then-nine Democratic candidates addressed the annual meeting of the National Congress of American Indians, the oldest and largest group representing tribal interests. "This is the first time that we've had such a turnout of the top candidates,'' Johnson said.

Several Democratic presidential candidates have openly courted the American Indian vote in other ways. Wesley K. Clark, Howard B. Dean, John F. Kerry and Dennis J. Kucinich have devoted space on their Web sites to explain their positions on issues of interest to American Indians, including tribal sovereignty. The Democratic Senatorial Campaign Committee has created its own "get out the vote'' effort in states with large numbers of American Indians. The Republican Senatorial Campaign Committee plans to gather with tribal leaders in late February to plot political strategy.

"We expect to have a bigger bloc of [American Indian] voters coming out on Tuesday than we've ever had in the past because of the candidates' outreach to Indian Country,'' Johnson said.

Nationwide, there are 2.5 million American Indians and Alaska Natives, comprising about 0.9 percent of the U.S. population, according to the U.S. Census Bureau. Another 1.6 million people reported in 2000 that their heritage includes American Indian or Alaska Native ancestry, as well as that of one or more other races. Many American Indians live on lands owned by one of the 562 federally recognized tribal governments, while others live in off-reservation or urban areas.

The federal government has had a roller coaster relationship with American Indian tribes. American Indians first won the right to vote 80 years ago as part of the Indian Citizenship Act passed in 1924.

Then, 50 years ago, Congress attempted to "terminate'' a number of tribes in Florida, California, Texas and other states. Tribes successfully fought back, but for many years afterward they turned inward, making little effort to connect with "outside'' political systems. Many Indians strongly believed -- and some still do -- that the doctrine of tribal sovereignty means they should remain completely independent.

Nearly two decades ago, Sen. Daniel Inouye, D-Hawaii, became chairman of the Senate Indian Affairs Committee and began pushing tribes to become more politically active. Inouye's idea was simple: if tribes wanted to improve their relationship with the federal government, they needed to help elect lawmakers who supported their cause.

American Indian political clout grew further after Congress passed the 1988 federal law that allows tribes to operate casinos and other gaming operations on their lands. More than 200 tribes now operate 321 casinos, and Indian gaming has become a nearly $13 billion annual business, according to the National Indian Gaming Commission.

A few tribes have become fabulously wealthy through their gaming operations. Recognizing the power of money in the American campaign system, those tribes and others have steadily increased their contributions to candidates who support Indian causes.

Political contributions to federal campaigns from American Indian gaming interests have risen from $1,750 in the 1990 election to $1.8 million in the first nine months of 2003, according to an analysis of Federal Election Commission figures by the Center for Responsive Politics.

"Clearly, Indian gaming interests have increased their contributions in recent years in an effort to wield more influence,'' said Steven Weiss, a spokesman for the center.

David Wilkins, a professor of American Indian studies at the University of Minnesota, agreed that Indian gaming has "provided some tribes, and I emphasize 'some,' with serious cash that gives them an opportunity to play a role in state and national politics... State and national political leaders also want to tap into that money for their own political purposes so they are finally listening to tribal nations.''

Even today, however, American Indians face obstacles in voting, Johnson said. National congress officials are working to ensure that voters can use tribal membership cards, as opposed to a driver's license, as proof of residency. That can be problematic because some tribal cards don't have picture IDs.

In addition, some addresses on tribal cards aren't precise because accurate addresses are not needed many reservations, Johnson said. "Everybody knows that Aunt Sally lives in the blue house around the corner. But that can become an issue for voting. We're trying to work these things out.''

Despite the obstacles, the increasing political influence of American Indians was substantiated in 2000, when Indian voters help Democrat Maria Cantwell unseat incumbent Republican Sen. Slade Gorton in Washington state. Gorton, often called "Darth Vader'' by tribal leaders, had staunchly opposed a number of American Indian initiatives.

American Indians flexed their political muscle again in 2002, when incumbent Sen. Tim Johnson, D-S.D., beat back a tough Republican challenger. Johnson won by 524 votes, and many political experts believe his support from American Indian voters made the difference.

In this year's election, American Indians again are aiming to make a political difference, said national congress President Tex Hall, chairman of the Mandan, Hidatsa and Arikara Nation of North Dakota.

Among the key issues are a push to solidify tribal sovereignty, better funding for Indian health care and education, and an equitable solution to the decade-old fight over tribal funds held in trust by the federal government.

"In November, we will stand up in force to support those Republican, Democratic and Independent leaders who have honored this nation's commitments to tribes, and to send home those leaders who have disregarded us,'' Hall said.