“THE next mayor of Chicago will be Latino,” predicts John Hagedorn at the University of Illinois in Chicago. Latinos recently became the second-largest ethnic group in the city, accounting for 29.7% of the population, overtaking African-Americans (29.3%) and rivalling whites (32.6%). For decades the local Democratic Party’s machine was able to ignore Latinos. Today this would be political suicide. The closeness of Rahm Emanuel, Chicago’s mayor, to Luis Gutiérrez, a congressman and perhaps the city’s most powerful Latino politician, reflects this. On October 2nd Mr Emanuel, flanked by Mr Gutiérrez, who is of Puerto Rican origin, and dozens of Latino aldermen and city officials, announced that he is inviting “tens of thousands” of Puerto Ricans fleeing their hurricane-ravaged island to Chicago. About 1,600 have already arrived in the city. Gilbert Villegas, chairman of the city council’s Hispanic caucus, predicted that as many as 100,000 Puerto Ricans could pour into Chicago, which would double the city’s Puerto Rican contingent.

Chicago, which is a sanctuary city (meaning that it does not enforce federal immigration laws), is welcoming to Latinos. Undocumented migrants make up around 20% of the city’s Hispanic population. Mexicans are by far the biggest group, accounting for about 80% of the city’s 803,000 Hispanics. Puerto Ricans are the second-biggest group, followed by a medley of Central Americans. They tended to cluster around the industries that hired them, and have stayed there: Little Village is predominantly Mexican, Humboldt Park is Puerto Rican and so on.

Gangs, which have tens of thousands of members, are omnipresent in Latino neighbourhoods. Even so, on nearly all measures of socioeconomic attainment Hispanics tend to do at least a bit better than African-Americans. Teenage pregnancies are still high, with 31.8 pregnancies per 1,000 Latinas aged 15-17, but lower than among black teenagers (43), says Sylvia Puente at the Latino Policy Forum, an advocacy group. (Nationwide it is the other way round.) Around 24% of Latinos live below the poverty line, compared with 33% of blacks. Crime is a big concern; but three-quarters of murder victims and murderers are black, whereas Hispanics account for only 12% of killers and their victims.

The first large group of Mexicans arrived in the 1910s to work in steel mills and slaughterhouses and settled in white working-class neighbourhoods among Poles, Czechs and Italians on the south-west and north-west side of the city. They now have their own museum, the National Museum of Mexican Art, which calls itself the largest Latino cultural institution in the country. They shop on their own version of the Magnificent Mile, Chicago’s central shopping avenue, a two-mile stretch on 26th Street on the south-west side lined with roughly 500 bodegas, taquerías, dulcerías and other bustling shops dubbed “the other Mag Mile”. The inaugural Latino theatre festival runs throughout October. Its largest show at the Shakespeare theatre is “Amarillo”, a wrenching tale about a Mexican immigrant.

The increasing power of Latinos has created tension with blacks, who have fled segregation, violence and unemployment in their old neighbourhoods in recent years. In 1970 Chicago had the second-largest black population in the country, 1.3m. It has 792,000 today. When Chicago’s black and Latino voters unite, as they did in 1987 to re-elect the city’s first black mayor, Harold Washington, they are a powerful force. When Chuy García, a Cook County commissioner who was born in Mexico, forced Mr Emanuel into a run-off at the last mayoral election, however, most blacks voted for Mr Emanuel, who is white and Jewish. Another Latino aspirant for the city’s top job might be more persuasive than Mr García. Susana Mendoza, the comptroller of Illinois, who is the daughter of Mexican immigrants, recently made waves when she chased down a hit-and-run driver. she may be the one to test whether it is still possible to appeal to both the city’s second- and its third-largest ethnic group.