Author of "Arizona: A History" Tom Sheridan, predicts what the history of Tucson will be one hundred years from now based Tucson's past one hundred years.

Arizona will continue to grow in the next century, and that means greater issues with water supply and a rise of power among Latinos and Native Americans, a historian says.

"Just as in the 20th century, water would be the defining issue," Tom Sheridan says. "There's no more pot of water at the end of Arizona's rainbow. We have all the water we're going to have, and we'll probably have less because of climate change.

"So the real interesting story politically in the coming century will be how we divide the water we already have."

Sheridan, who recently published a revision of his book Arizona: A History in time for the centennial, is a member of the research teams at the University of Arizona's Southwest Center and the School of Anthropology.

He predicts a rise in power for two demographic groups in the state in the coming century — Native Americans because of their water rights and Mexican-Americans because of their rapid population growth.

"One thing that's going to be really interesting is that Native Americans are going to be major players in that water game, because of the water rights that they've received, like the recent Gila River adjudication, which gives the Gila River Indian community over 600,000 acre-feet of water," Sheridan says.

What he characterizes as the "worst assault on Mexican people and Mexican culture since early statehood" will change soon because of population shifts.

"That's going to change very, very quickly, and I think the politicians who are pandering to that are going to pay the price," he says. "Hispanics are the fastest growing segment of Arizona's population. They're the youngest; they're the most fertile, and I think the Arizona 100 years from now will be much more Latino and much more Native American than it is now."