WASHINGTON (AP) — Barack Obama was the overwhelming choice of the one in 10 voters who went to the polls for their first time today — a racially diverse group of mostly twentysomethings, half of whom call themselves Democrats.

One in five of the new voters was black, almost twice the proportion of blacks among voters overall. Another one in five of the new voters was Hispanic. About two-thirds of them were under 30 years old.

These first-time voters, a key element of Obama's strategy, were turning out for him over Republican John McCain by about a 3-1 margin, according to preliminary exit poll results.

Young voters tend to favor Democrats, but not in such high numbers. In 2004, John Kerry won 53 percent of their votes.

A third of first-time voters this year said they were political independents; only about one in 5 was a Republican.

Twenty-six-year-old Jennifer Sunderlin, who typically votes Republican, said she didn't stick with her usual party this election year.

"Don't tell my Dad, but I voted for Barack Obama," said Sunderlin, of Albany, N.Y. She said she was turned off by McCain's choice of Alaska Gov. Sarah Palin as his running mate.

She wasn't alone. Four in 10 voters overall said Palin was an important factor in deciding who to vote for, and this group leaned slightly toward Obama. But nine in 10 Republicans calling Palin's selection important were voting for McCain.

Andrew Greenaway, 18, said he was swayed by all "the buzz" about Obama in his dorm at Cleveland State University. "All my buddies told me to vote for Obama," he said.

In contrast, voters age 65 and over favored McCain. And he also drew strength from white, working-class voters. Whites who haven't finished college were giving him support similar to the 23-point margin by which President Bush won them in 2004.

About a third of voters said the quality that mattered most was the candidates' ability to bring about change — the mantra of Obama's campaign — while a fifth focused on the candidates' experience, McCain's strong point.

"I don't think Obama knows what he's doing," said Craig Burnett, 55, a Republican in Hagerstown, Md. "He's too young and inexperienced."

More than half strongly disapproved of the way President Bush has handled the job.

Two-thirds of voters worried about how to pay for health care and at least as many feared terrorists will attack the U.S. again. But the economy weighed heaviest on their minds.

Six in 10 voters picked it as the most important issue facing the nation, according to preliminary polling. None of the four other issues listed by exit pollsters — energy, Iraq, terrorism and health care — was picked by more than one in 10 people.

Almost everyone agreed the economy's condition is either "poor" or "not good." And more than eight in 10 said they were worried about the economy's direction over the next year.

Half of voters said they're very worried the current economic crisis will harm their families, and another third were somewhat worried about that. One reason: about two-thirds of voters have stock market investments, such as retirement funds.

Yet there was room for optimism — nearly half predict the economy will get better over the next year.

In a historic year, when Obama could become the first black president, nine out of 10 voters said the race of the candidates wasn't important to their votes. Almost as many said age wasn't important, a nod to 72-year-old McCain.

The results were from exit polling by Edison Media Research and Mitofsky International for The Associated Press and television networks conducted in 300 precincts nationally. The preliminary data was based on 10,747 voters, including telephone polling of 2,407 people who voted early, and has a margin of sampling error of plus or minus 1 percentage point for the entire sample, smaller for subgroups.