“I teach my kids to wash their hands before they eat,” said Bob Richardson, a resident of East Rancho Dominguez, an unincorporated part of Los Angeles County adjacent to Los Angeles, where street vending has become more common in recent years. “I don’t know what those people do before they serve the food. I believe it’s unsafe, and it should be outlawed.”

But the current efforts to legalize street vending is evidence of a shift in attitudes toward immigrants — and street food — here in the two decades since the last major push to legalize street vending two decades ago amid an anti-immigrant fervor in the state.

These days, food aficionados and Pulitzer Prize-winning critics debate which stand serves the best $1 tacos al pastor.

“For a long time in Los Angeles, the feeling was that street vending was a third world activity, not worthy of the Anglo version of Los Angeles that emerged in the mid-20th century,” said Mark Vallianatos, an instructor of urban and environmental policy at Occidental College here, who has been part of the campaign to legalize street vending.

But Latinos now make up about half of the city’s population, and an estimated one in 10 residents of Los Angeles County are immigrants in the country illegally. Mayors past and present have called vigorously for federal immigration reform, and the police chief has publicized policy changes intended to reduce deportations of illegal immigrants arrested for minor crimes.

“Now, being pro-immigrant is a winner in L.A.,” Mr. Vallianatos said. “Street food has become hip and popular all over the city, not just with low-income Latinos. People are starting to see it as part of what makes our city great.”

The vendors have tried to frame their struggle as a fight for human dignity, drawing connections with the fight for an immigration overhaul.