Washington ? White, rural and homogeneous. New Hampshire and Iowa play big roles in choosing presidential candidates but don’t look much like the rest of the country.

A better bellwether might be Illinois. It’s the most average state, according to an Associated Press analysis of data from the Census Bureau.

Illinois is the fifth largest state, with a big city in Chicago, rolling countryside in the south and a lot of sprawling suburbs. And it has Peoria, which, it turns out, really is a barometer of America’s preferences. Many companies continue to use the city in central Illinois as a test market, taking literally the adage about how things play there.

“Illinois has always been a mirror of America,” said state Sen. Kirk Dillard, a Republican. “With all due respect to South Carolina, Iowa and New Hampshire, they are not reflective of the overall American population.”

The AP ranked each state on how closely it matched national levels on 21 demographic factors, including race, age, income, education, industrial mix, immigration and the share of people living in urban and rural areas. The rankings were then combined to determine the state that best mirrors the country as a whole.

Illinois was followed by Oregon, Michigan, Washington and Delaware.

West Virginia was the least typical state – poorer, whiter, more rural – followed by Mississippi, New Hampshire, Vermont and Kentucky.

Iowa ranked 41st, meaning nine states and the District of Columbia look less like the country as a whole. South Carolina, which also has an early primary, ranked 24th.

America is becoming more diverse, with minorities topping 100 million for the first time in 2006, according to Census Bureau figures being released today. About one in three Americans was a minority last year, a slight increase.

In 2006, the nation was 67.6 percent white, non-Hispanic; 15 percent Hispanic; 13.4 percent black; 5 percent Asian; 1.5 percent American Indian or native Alaskan and 0.3 percent Hawaiian or other Pacific Islander. The percentages add up to more than 100 in part because some people identify with more than one race and Hispanics can be of any race.

Illinois’ racial composition matches the nation’s better than any other state. Education levels are similar, as is the mix of industry and the percentage of immigrants. Incomes in Illinois are a little higher and the state is more urban the rest of the nation. But the age of the population is very close to the country’s mix of minors, seniors and those 18 to 64.

The Illinois Senate approved a bill Tuesday that would move the state’s presidential primary from March to Feb. 5, and Gov. Rod Blagojevich has promised to sign it. Once he does, Illinois will join a growing number of states trying to increase their clout by scheduling earlier primaries.

An argument sometimes cited for the moves: increasing the diversity of voters early in the primary season. “States that are quite vanilla ought not to be making the decisions for us,” said Illinois House Majority Leader Barbara Flynn Currie, a Democrat.

Iowa and New Hampshire have played prominent roles in choosing presidential candidates for years, with Iowa holding caucuses in January and New Hampshire holding the first primary. Both states are more than 90 percent white, making them among the least diverse in the country.