“Unfortunately, African-American communities in Chicago are faced with extraordinarily high unemployment rates — there’s just an ongoing, really dire economic crisis,” said Martha Biondi, chair of the African-American Studies Department at Northwestern University. “And instead of blaming employers or the leaders of the major parties, many people who are suffering will sometimes blame immigrants or working class rivals. They will say, ‘There’s this other group that’s getting the jobs.’ ”

Mr. Garcia, 58, who has won election to the City Council, the state Senate and the county board of commissioners, has been one of the most prominent Latinos in elected office here, beginning in the 1980s. If elected, he would be the city’s first Latino mayor.

From the start of his campaign, he spoke of building a multicultural coalition in the spirit of Harold Washington, the city’s first black mayor, on whose campaign Mr. Garcia worked.

He has reached out to black leaders, collecting endorsements, campaign donations and promises of votes. And he has focused his campaign on concerns Chicagoans share, including improving public education, a higher minimum wage, reducing gun violence and modernizing mass transit.

But across this sprawling city, blacks and Latinos tend to live in different neighborhoods and attend different churches.

“Chicago is so segregated — black people live in their neighborhoods and Hispanic people live in their neighborhoods. They don’t have any interaction,” said Mike Butler, who is African-American and in his 60s, as he attended a campaign event for Mr. Garcia this week. “I’ve heard people say, ‘If we let him in, he’s going to be hiring all his people,’ but I tell them, don’t be so backward.”