Members of the Chamber of Commerce in the central Mexican state of Guanajuato have said they plan to join the boycott too, as have officials in the border states of Tamaulipas, Chihuahua and Coahuila. Sonora state, which borders Arizona, is not supporting the boycott.
But Mexican diplomats and President Vicente Fox are said to be afraid that the boycott could backfire.
"The Mexican government will not join boycotts of this nature," Foreign Minister Luis Ernesto Derbez said last week. All Mexican embassies and consulates in the U.S. will remain open.
On Tuesday, supporters of leftist presidential candidate Andres Manuel Lopez Obrador passed out fliers in support of the boycott at a campaign rally in Mexico City. But center-right candidate Felipe Calderon said he opposed the action.
"I've felt the temptation to show solidarity with the movement," Calderon said in an interview. But "it's important to understand that the immigration problem can't and shouldn't become a conflict between countries."
Calderon said he worried that the boycott would lead to an even greater "anti-Mexican" sentiment in the U.S.
Ernesto Zamora, a 65-year-old Mexico City retiree, said his family would honor the boycott even though it didn't buy many American-made products. His son, who left for Los Angeles to work in construction some years back, called to tell his father about the boycott.
"We can show the support of Mexico for the Mexicans who are over there," Zamora said of the boycott. "They're good workers and it's not right that they want to send them back."
Times special correspondent Alex Renderos in San Salvador contributed to this report.