As the sun set, Roy Wood looked out of place patrolling a dirt road a few steps north of a rusty fence that separates the United States from Mexico. The clean-shaven English-as-a-second-language instructor wore a T-shirt tucked in clean blue jeans, a pistol strapped to his belt.

Many of the hundreds who make up the self-appointed civilian patrols monitoring the border to deter smuggling of people and drugs are unemployed or underemployed ex-military men who resent Mexicans who come to the United States illegally and, in their view, compete for jobs, crowd hospitals and schools and threaten English as the nation's dominant language.

The civilian patrols of recent months have failed to stem the tide of illegal crossings, but they have ratcheted up pressure on Washington to better police U.S. borders and fueled tension in border towns about potential violence. But as the patrols continue, they are targeting a wider circle of volunteers.

Urban dwellers, young women, some Hispanics have joined. Their gripes are often the same as those of the gun-toting veterans, though their backgrounds are different.

"It shows that the problem reaches all of America, not just a specific group," said Gayle Nyberg, 57, of Murietta, Calif., who slept in the back of a 1976 Chevrolet Suburban while on patrol duty.

More than 200 people signed up with the California Minutemen, who spent three weeks at the border over the summer.

Civilian patrols are opposed by 56 percent of Californians but supported by a majority of Republicans and people age 65 and older, according to a recent Field Poll. Support was weak in Los Angeles and San Francisco and among Hispanics and people younger than 40. The telephone survey of 426 registered voters Aug. 19-29 had a margin of error of plus or minus 4.9 percentage points.

Two dozen or so recruits gathered one August evening in Campo, 40 miles east of San Diego, where many had been camped for nearly three weeks. Small groups were assigned along a mountainous 16-mile stretch of the border.

No one spotted illegal crossers that night, which is typical. The Border Patrol credits the California Minutemen for reporting crossings that resulted in three arrests during a three-week patrol.

Volunteer Gayle Nyberg of the border watch group California Minutemen peers over a border wall to look for illegal immigrants from Mexico.