Republicans believe high unemployment will be Barack Obama's weak point this November. So why has Matt Caffrey, a 22-year-old from Ohio, just quit his job?

To help the president get reelected.

Leaving a secure job in a country with an official unemployment rate of 8.3 percent, and broader estimates in the double figures, is not for the timid.

But six months into his first fulltime job, a two-year contract with an environmental advocacy group, Caffrey decided nothing could be more important than campaigning to get Obama another four years.

So on the eve of a business trip, he called his boss.

"It was something I agonized over -- for a few minutes," Caffrey, a bearish figure in student-style sweatshirt and running shoes, said with a grin.

Back in 2008, Caffrey was one of the excited foot soldiers in a youth movement helping propel Obama from obscurity to the White House.

As president of the college Democrats at Ohio State University, he was on the front lines and his face still lights up when he recalls the "amazing" experience.

So when an opportunity came to fill a paid, but temporary position as a Obama campaign field organizer in the Ohio capital Columbus, Caffrey jumped. "I didn't want to feel 50 years from now that I could have done more in this very magic moment," he said.

Youths have long tended to vote Democratic, but in 2008 Obama's fresh looks, sense of style, and stirring speeches inspired nothing short of adulation. In an election with heavy youth turnout, under-30's supported Obama over John McCain by a margin of about 68 to 30 percent.

The question now is whether Obama's army of idealistic youngsters can muster that same energy.

Obviously the thrill of electing the first black man to the nation's highest office can't be repeated.

Also, Obama is no longer the fantasy figure he was to many liberals last time. After four years of presiding over a sick economy and disappointing supporters on several big promises, like the failure to close the prison at Guantanamo, Obama has baggage.

According to CIRCLE, a non-partisan research group specializing in youth electoral issues, young people so far show no sign of great interest in the Republican primary candidates battling to take on Obama.

Maverick Republican candidate Ron Paul is frequently touted as a favorite with libertarian-minded youths, but statistics show that even his level of support in that age group fails to match Obama at the same stage during his primary battles four years ago.

"Barack Obama drew far more votes in primaries and caucuses from Americans under 30 in his 2008 campaign than all the Republican candidates combined," CIRCLE said.

Perhaps what could hurt Obama is sheer lack of interest.

One hint of weakness in Obama's youth base is the Occupy movement, which sprang up last year in New York, before spreading nationwide.

The young, often well-educated and deeply leftwing Occupy members resemble natural Obama supporters. Yet many Occupy activists say they have turned their backs on a politician they describe as having sold out to Wall Street interests.

"Especially with the younger people, there's this idea that 'all the politicians are lousy and I'm not voting for any of them,'" Connie Everett, a spokeswoman for the Occupy movement in Columbus, said.

"There are people who just feel the system is completely dysfunctional and corrupt and many people just don't want to do anything that feeds into that system."

At a rally this week in Ohio for Rick Santorum, just behind Mitt Romney in the race for the Republican nomination, Bill Harkenrider, 20, was one of the few college age people in a room of several hundred.

"I usually hang out with Republicans," he said, explaining that he liked Santorum's forthright manner and emphasis on sticking to the letter of the US constitution.

Asked why his peers tend to vote Democratic, before in some cases turning Republican when they're older, Harkenrider said: "It's because of the teachers, the people who influence them. Then the reason it changes is that they get out into the real world and pay taxes. Young people don't know about that."

Kyle Schmidlapp, a 23-year-old training to be administrator at a nursing home, said he voted for Obama in 2008 but switched after leaving college.

"I was excited then. Not now, though," he said. "I don't know if it's because I've grown up more, or because then I was in college and got a job."

However, for every disillusioned former Obama supporter there may be others just as determined to combat an increasingly rightwing Republican Party, particularly over abortion and other hot-button social debates.

"I'll vote for Obama hands down," said Madeline Fuller, an Ohio high school student who will turn 18 and be eligible to vote for the first time just before the presidential election.

"On social issues I'm very, very liberal. I think a lot of the people I go to school with are leaning towards Obama."