INDIANAPOLIS (AP) — Hillary Rodham Clinton's campaign message that Americans want "jobs, jobs, jobs" resonated in Indiana's Democratic presidential primary, with voters concerned about the uncertain economy favoring the former first lady over Barack Obama.

Clinton narrowly won Indiana's primary after facing a strong challenge from Obama, who drew support among blacks, young, first-time primary voters, college graduates and liberal voters.

While Clinton's economic message helped her win the votes of two-thirds of Indiana's working-class whites who voted, nine in 10 Indiana blacks backed Obama, according to preliminary data from exit poll surveys.

The outcome of the primary was in question until thousands of votes from heavily black Lake County in the state's northwestern corner were finally returned early Wednesday morning after delays attributed to the large number of voters there. Clinton won the state with about 51 percent of the vote in a primary that saw record turnout, according to unofficial tallies by The Associated Press.

Hours earlier, Clinton claimed victory during an Indianapolis speech and pronounced Indiana the tiebreaker in her favor.

The New York senator had made jobs a key message in repeated campaign visits to the state, and two-thirds of Indiana voters interviewed after leaving polling places Tuesday said the economy was their top concern.

Preliminary data from exit poll surveys showed those voters were more likely to vote for Clinton, who did well with Indiana's white working-class voters following her strong showings with that group in Ohio and Pennsylvania.

Four in 10 voters said the economic slowdown has affected their family a great deal, while nine in 10 said their family had been affected at least somewhat.

Indianapolis bus driver Daron Washington Sr. said Tuesday he voted for Clinton because he was hoping she could bring back the better economic times that prevailed under her husband, former President Bill Clinton.

"I like the way her husband ran the country, and I'm more familiar with her," he said.

Obama led with young and very liberal voters and had a small edge among college graduates and first-time voters, according to the exit polls conducted for The Associated Press and the television networks.

Clinton and Obama split the votes in Indiana of whites under age 30 and people earning at least $100,000 a year — groups that usually have leaned toward Obama.

Six in 10 whites supported Clinton, as the racial divide seen in most contests this year continued. Older voters and Catholics — two other important voting blocs — backed Clinton, as they have done consistently this year.

Clinton made a strong showing among white men, a group she and Obama have generally split about evenly but whom she won handily in Pennsylvania and Ohio. In Indiana, about six in 10 white men voted for Clinton.

But as the fight for the Democratic presidential nomination continues, the exit polls showed that many Hoosier Democrats might vote for certain Republican presidential nominee John McCain, who won in Indiana Tuesday, if their preferred candidate is not on the ballot in November.

About one in five Obama voters said they would vote for McCain in a Clinton vs. McCain matchup, but one of three Clinton voters said they would vote for McCain if Obama wins the nomination.

About half the Indiana voters said the controversy over the Rev. Jeremiah Wright was an important factor in their decisions. But the focus on statements by Obama's former pastor was not giving Clinton much of an edge, according to the surveys.

About seven in 10 of those who said Wright was important in picking a candidate were voting for Clinton — including about eight in 10 whites who said so. But just about balancing that out, about half said the pastor was not a big factor in deciding how to vote. Of that group, about two-thirds were supporting Obama.

Although the economy was voters' top concern, about one in five said the war in Iraq was the top issue in the election. Those voters favored Obama.

The preliminary results were from exit polling by Edison Media Research and Mitofsky International for The Associated Press and television networks. There were 1,738 voters in the Indiana Democratic primary who were interviewed, for a margin of sampling error of plus or minus 4 percentage points.