"Patrick Buchanan? He don't like the Mexicans, the son of a bitch," said Gilberto Monteverde, manager of Ernesto's Boots and Repair. Mr Buchanan, the rogue Republican who looks as if he may win his second primary here in Arizona, has touched a nerve along the small businesses dotting 7th Street, the main drag leading through Hispanic south Tucson.
The candidate came face to face with his own rhetoric when he joined the parade for La Fiesta de Los Vaqueros, an annual rodeo that draws Mexican and American cowboys for calf-roping, bull-riding, and steer-wrestling. His float was roundly jeered, and as police dragged off a protester who tried to block the parade, the crowd chanted "Let him go. Let him go".
Later, at a Tucson community centre, Mr Buchanan made his standard promise "to stop this massive illegal immigration in this country cold". Marciano Murillo, an 18-year-old student, came closer than any Republican rival to shouting him down. "The Mexicans come over here to work. They help this economy!" he yelled. "Why do you speak only of the Hispanics and the Mexicans that are on welfare when you have millions of Caucasians and African-Americans on welfare?"
The stakes seem high in tomorrow's Republican primary in Arizona, which has been cast as the West's answer to New Hampshire. Senator Bob Dole is looking for a win, and publisher Steve Forbes has pinned many of his hopes here. One poll gave Senator Dole a slim lead with 25 per cent, Mr Buchanan 21 per cent and Mr Forbes 19 per cent. Former Governor Lamar Alexander is running a weak fourth.
All three front-runners were in the state this weekend, booking back- to-back radio and television advertising. An expected low turn-out could favour Mr Buchanan, backed by an enthusiastic coalition of conservative Mormons and fundamentalist churches against abortion, and gun-rights activists and far-right groups in rural areas of the state. But a large percentage of Republican women, who tend to vote more moderately, are undecided.
Mr Buchanan, a former speech-writer for Presidents Nixon and Reagan, knows all the buttons to push in Arizona, home turf for conservatives. He got a standing ovation at a "Right to Life" forum when he denounced abortion even for the victims of rape. There were cheers at a candidates' debate when Buchanan spoke of a "foreign invasion" from the south and promised to wall off the Mexican border.
The Arizona race offers a taste of how immigration will play in the big states of Florida, Texas and California, not just in the primaries in March but in the general election in November. Republicans have often played the race issue but usually hedge that they are only opposed to illegal immigration, not legal. Bill Clinton, eager not to cede this fertile territory, has publicly boosted border security. Several key crossing points for the several hundred thousand people estimated to enter the US illegally every year are already barricaded Berlin-style with iron fences, spotlights, and hi-tech surveillance gear.
A sprawling, stylish, and mostly Democratic city, Tucson is a short freeway ride north from Mexico, often a staging post for immigrants. Back from 7th street are neighbourhoods rife with drugs and drive-by shootings. But even among the old Hispanic families in Tucson, people have no doubt that Mr Buchanan is playing the race card. "What does illegal mean to them?" asked Gilberto Monteverde's wife Helen, whose family has been American for generations. "Somebody that's dark, that looks Mexican. It's everybody, it's all of us that are going to have problems."