TUCSON—The contest to replace Republican Rep. Jim Kolbe, who is retiring, in Arizona's 8th District is going to be fierce. The district is ground zero in the debate over illegal immigration. "It's not an issue where there seems to be a lot of gray," said Blake Morlock, who is covering the race for the Tucson Citizen. "It seems to be black or white. Either people say, 'Let them stay,' or 'Get them out of here.' "

Why here? Because of a change in federal border policy that dates back to the Clinton administration. Border Patrol agent Gustavo Soto explained, "The operation the Border Patrol ran in the mid-1990s effectively shut down routes [from Mexico into] California, Texas, and certain parts of New Mexico." Operation Gatekeeper began on the California border in 1995. According to the Justice Department's Office of the Inspector General, "The purpose of the new plan was to stem the tide of illegal immigrants crossing the border from Mexico into the United States and to shift the remaining traffic eastward, where the Border Patrol believed it enjoyed a strategic advantage."

Gabrielle Giffords, who is running for the Democratic nomination in the 8th District, says, "We now see a strategic decision by the federal government to force immigrants to come through our deserts. We have hundreds of these people die in the deserts every year. There is a disaster along the border."

John Fife, an immigration activist and a retired Presbyterian minister, says, "It is only since the Clinton administration's militarization of the border and quadrupling of Border Patrol agents, along with the new technology and the walls, that the migration pattern has shifted into more and more isolated and hazardous areas. Prior to that, there were no deaths along the border."

According to Soto, agents capture 1,500 to 2,000 illegal immigrants in the Tucson sector every day. "We account for almost half of the apprehensions nationwide," he says. "It is the last frontier."

In Arizona, the surge of illegal immigrants is causing immense difficulties, including security problems. Among the unanticipated concerns is environmental destruction. Pull 50 yards off Interstate 19 running between Nogales on the border and Tucson, and you can see piles of discarded clothing, food containers, plastic water bottles, and backpacks. "Ecologists tell me the Sonora Desert is going to take 100 years to recover from the damage," Fife observed.

Illegal immigration bitterly divides this district. Republican candidate Randy Graf is rallying supporters of tougher border controls. "We've been looking at this as a law enforcement issue, but I believe there is a military aspect to this," he said. Graf accepts the support of the Minutemen, the volunteer citizen patrols that monitor border areas and report sightings of illegal immigrants.

On the other side are the Samaritans, an organization of volunteers that sets up camps and water stations in the desert and provides medical assistance. Are the volunteers encouraging illegal immigration? "Humanitarian aid is never a crime," say lawn signs and bumper stickers around Tucson. In Fife's view, "The solution is not in walls or militarization. It is in a new set of policies that recognize the realities of the relationship between Mexico and the United States."

The political split can be unpredictable. Morlock of the Citizen reports, "You've got Republicans who are in favor of the guest-worker program. You've got liberal Democrats who say, 'Get them all out.' It really cuts across party lines."

Democrat Giffords argues, "We need a guest-worker program. That's the bottom line." That is the position taken by President Bush, Sen. John McCain of Arizona, and Rep. Kolbe—all Republicans. But Republican Graf says, "I just flat disagree with the congressman and our senator and the president." Last week, Gov. Janet Napolitano signed an executive order to deploy additional National Guard forces at the border. She's a Democrat.

"There is a visceral response to illegal immigration," Morlock says. "It would be difficult to have a rational conversation with someone about it, on either side of the issue."