In 1990, non-Hispanic whites were the majority population in 70 of the 100 largest US cities, making up 52% of the total.

Hispanics are the fastest growing urban group in the US, according to the census - increasing at a rate of 72% in the 20 fastest-growing cities, compared to 5% for whites.

Overall, US cities gained 3.8 million Hispanic residents, an increase of 43% on 1990.

Chicago, the third-largest city in the US, grew in the 1990s for the first time since 1950, partly due to an influx of over 200,000 Hispanics.

Boston, Dallas and Los Angeles would all have probably decreased in size in the 1990s but for Hispanic growth.

Implications

The change in demographics is likely to have a significant impact on public policy, Bruce Katz of the Brookings Institution told The New York Times.

Cities may have less money to work with, for example, because the average household income for a Hispanic family is about $14,000 per year less than for a white family.

Hispanic families therefore tend to pay less tax.

At the same time, they also tend to have more children than white families, placing greater demands on the education system.

The change is already making itself felt in politics, with the son of a Mexican immigrant, Antonio Villaraigosa, hoping to become the first Hispanic mayor of Los Angeles since 1872.

However there is no correlation between increased population and greater political power.

The New York Times pointed out that non-Hispanic whites are a minority overall in California, but nearly 75% of Californian voters in last November's elections were white.

At the same time, only 36% of California public (state) school pupils are white.