(CNN) -- Severe worries about the economy drove the votes of Wisconsin Democrats on Tuesday, and Illinois Sen. Barack Obama won most of those votes, according to exit polls conducted for CNN.
Exit polling results showed Obama either leading comfortably or pulling nearly even with New York Sen. Hillary Clinton among almost all demographic groups -- including the blue-collar workers and women that Clinton had considered her base -- to take his ninth victory in a row in the race for the Democratic presidential nomination.
With its strong industrial base, Wisconsin has been considered by analysts a possible indicator of how the vote may go in major upcoming primaries in states like Ohio and Pennsylvania.
In exit polling of 1,431 voters, Obama took 55 percent of the vote, compared to 44 percent for Clinton. Based on those polls and early returns, CNN called the primary for Obama shortly after polls closed at 9 p.m. ET. Watch how Obama is cutting into Clinton's base »
The exit polls showed 44 percent of Democratic voters said the economy was the most important issue in deciding their vote -- followed by the war in Iraq at 28 percent and health care at 26 percent.
Fifty-five percent of those who cited the economy voted for Obama, compared to 44 percent for Clinton.
An overwhelming 90 percent of the Democratic voters polled said the nation's economy is either "not so good" or "poor."
And 71 percent said U.S. trade with other countries causes the loss of American jobs, while only 17 percent said it creates jobs and 9 percent said it has no effect.
Those who felt trade causes job loss also favored Obama, 55 percent to 43 percent.
Voters in virtually every contest this season have cited the economy as their chief concern. But the poll of Wisconsin Democrats suggests a particularly bleak view of the nation's financial well-being.
Since the first caucuses, in Iowa, Obama has polled the best among black, more wealthy and educated voters and college students while Clinton -- until last week's Maryland and Virginia primaries -- did better with women, low-income voters and blue-collar workers.
As such, Wisconsin was originally believed to be a state she should win.
"The demographics -- poor, union, a lot of Catholics -- have all gone well for Hillary Clinton so far," said CNN senior analyst Jeffrey Toobin shortly before polls closed. "If she doesn't do well here, it shows her support is slipping away."
But Obama beat Clinton among people who said they have a union member in their household -- 54 percent to 45 percent for Clinton -- and stayed close among women, trailing Clinton 51 percent to 48 percent.
Clinton edged Obama narrowly among Catholic poll respondents -- who made up 41 percent of voters interviewed -- 50 percent to 48 percent. She also held narrow leads among voters with only a high school education, people 60 or older and those making between $15,000-$30,000 a year.
But Obama kept those margins close and took easy wins among his traditional base of supporters.
Among voters 49 years old and younger he had a significant 57-40 percent edge over Clinton. College-educated voters, who made up 72 percent of those polled, favored him 58 percent to 40 percent.
Obama had a slight edge among voters who called themselves Democrats -- 51 percent to 48 percent -- but overwhelmingly topped Clinton among the 27 percent of respondents who called themselves independents, taking 62 percent of their votes to Clinton's 34 percent.
Both senators had campaigned on the economy Tuesday.
"Over the last few weeks, we've heard a lot about how our economy is sliding towards recession," Obama said in San Antonio, Texas. "And as I've traveled across the country, I've seen the face of our sluggish economy."
Meanwhile, Clinton told an audience in the Cleveland suburb of Parma, Ohio, that more needs to be done to aid cities.
"I think we have to think more creatively. We can't just do the same things over and over again," the senator said.
Both Democrats and Republicans held primaries in Wisconsin on Tuesday, while only Democrats were competing in Hawaii's caucuses and only Republicans had delegates at stake in Washington state.
CNN is not reporting exit poll data from Washington or Hawaii.
Going into Tuesday, Obama lead Clinton in the overall count of delegates to the Democrats' August nominating convention in Denver, Colorado -- 1,262 to 1,213, according to CNN estimates.
The estimate includes the support of superdelegates, the party officials and elected officials who are free to vote for any candidate at the party's national convention. Neither candidate is likely to to win the 2,025 delegates needed to win the nomination before the party convention. There are 74 delegates at stake for Democrats in Wisconsin.
While much has been made of Clinton's gender and Obama's race in the Democratic contest, an overwhelming majority of Democratic voters in Wisconsin said neither factored into their decision.
Eighty-four percent of respondents said the candidate's gender was not important to them and 86 percent said race was not important.
About 87 percent of the poll's respondents were white, 57 percent were female and 43 percent were male.
Obama would be the first black candidate to win a major U.S. party's presidential nomination while Clinton, the former first lady, would be the first woman. E-mail to a friend