WASHINGTON – He promised change, and he looked the part. No longer.

The Barack Obama of 2011 is a chief executive who confronts enormous challenges, chief among them the economy, as he starts building a re-election campaign far different from the juggernaut of optimism and trajectory that vaulted him to the White House.

He's the incumbent facing the daunting task of convincing a nation burdened by high unemployment that he has delivered change, made the right moves and earned the chance to continue the job.

"Ultimately, I'll be judged as president as to the bottom line, results," Obama said after the Democrats' November election "shellacking." Democratic losses set the stage for divided government, gave Obama a chance to shift to the center by compromising with Republicans and led to White House staffing changes that signal the start of Obama's re-election drive. It will ramp up in the coming months.

The Democrat's hurdles are great.

Obama owns the slow-to-recover economy and is the face of a Washington he once campaigned against. Polls show his diverse voting coalition from 2008 cracked and his support among independents weakened. His path to Electoral College victory in 2012 is tougher. And he doesn't have George W. Bush's unpopularity paving the way for a Democratic victory.

But the upsides are huge, too.

His personal popularity is still high and he has the White House bully pulpit. He's a proven record fundraiser and he has no primary challenger. The brain trust of Obama's first campaign will run the second. Also, there's no obvious Republican rival in a crowded GOP field.

This president has accomplished more in two years than many of his predecessors did in two terms.

After preaching bipartisanship as a candidate, Obama the president leveraged huge Democratic majorities in Congress to produce a series of legislative achievements: the health care overhaul, new financial rules and an economic stimulus measure. He declared an end to the combat mission in Iraq and, while bolstering U.S. forces in Afghanistan, he has pledged to start pulling troops home.

It's a record that could help or hurt his prospects depending on the whims of an electorate that has shown itself impatient with spotty progress amid economic turmoil.

The issue is certain to dominate the campaign.

"This will be about the economy," said White House press secretary Robert Gibbs. "It was when we were last playing presidential politics, and it will be when we start again."

Economists predict the unemployment rate won't fall considerably before the election. White House officials privately acknowledge that they don't expect a complete economic turnaround. They're banking on good economic news — like the Friday report that unemployment slipped to 9.4 percent in December — will continue over the next year, allowing Obama to argue that he's overseeing a rebirth and, thus, shouldn't be fired.

"We know these numbers can bounce around from month to month, but the trend is clear," Obama said Friday, already trying to make the case.

History shows that the argument can work.

Despite 7.4 percent unemployment in October 1984, President Ronald Reagan was re-elected because the economy was steadily improving — and people felt it.

"We need two strong years of economic growth and a significant reduction in the unemployment rate. It needs to be moving in the right direction," said Steve Murphy, a Democratic consultant on Obama's first campaign. "If we're able to withdraw our forces from Iraq on schedule and largely able to withdraw our forces from Afghanistan, that's going to be well received here, too."

Still, as other incumbents before him can attest, a troubled economy sometimes is an insurmountable obstacle. Democratic President Jimmy Carter lost in 1980 and Republican George H.W. Bush came up short a dozen years later.

There are other lessons Obama can learn from previous presidents.

Following a 1994 drubbing, Democratic President Bill Clinton showed how working with a Republican-controlled Congress could put him on solid footing for re-election with independent voters who play a pivotal role in general elections.

Obama seems to be using that playbook now that Republicans run the House. He's embracing an opportunity to govern in a more bipartisan manner as he did in compromising with the GOP on tax cuts at the end of last year.

The strategy could help him win back crucial supporters: independents and his broad coalition of first-time voters who were attracted to his call for a new approach to politics and carried him to victory in 2008. They didn't turn out for his Democrats two years later. Obama wasn't on the ballot in November, but he acknowledged coming up short in his promise to change how Washington works.

Winning 270 electoral votes depends on that support.

Obama reached the magic number in his first campaign by aggressively turning out new and infrequent voters, especially young people, in states that aren't usually contested. The effort paved the way for victories in GOP-leaning states such as Indiana, North Carolina and Virginia, giving him enough electoral votes to win the White House.

Two years later, Obama's job approval rating in those states and others is languishing under 50 percent, and Obama aides privately acknowledge the map is more difficult.

"He has to do a two-step dance: recapture those independents who moved to a different place in 2010 and re-energize those new voters who came out in 2008," said Jamal Simmons, a consultant at the Democratic National Committee during Obama's campaign. "If the electorate looks anything close to the way it looked in November 2010, Barack Obama could part the Red Sea and he would have a very hard time getting re-elected."

The next campaign has been in Obama's sights since just after he won the first.

That's when advisers decided to house the backbone of the campaign — a grass-roots mobilizing and fundraising operation called Organizing for America — at the DNC. Since then, staffers have been updating a contact list that numbers more than 13 million. The DNC long has collected research to use against prospective GOP candidates should they win the nomination.

Obama's top political advisers have been sketching the campaign's broad strategic plan for the past several months, including setting a goal of raising far more than his record $750 million haul. White House advisers have signaled that Obama wouldn't oppose Democratic-leaning independent groups raising money to run ads given the onslaught by GOP-aligned outside groups such as American Crossroads in 2010.

Obama's core political team remains the same as 2008. White House senior adviser David Axelrod is to advise the campaign in his hometown of Chicago. Gibbs is stepping down to become a campaign consultant. Obama's first campaign manager, David Plouffe, is joining the White House next week with a political portfolio. White House deputy chief of staff Jim Messina is to leave by month's end to run the campaign from Chicago.

The president's team hopes that by anchoring the campaign in Chicago, it can stoke the grass-roots feel of the first campaign and counter the notion that Obama has become a creature of Washington. Most incumbents — including Reagan, Clinton and both Bushes — have kept their campaigns in close proximity to the White House to ensure continuity with the power center.

It may just be fitting, as well, for a president who has a record of defying convention, and, come 2012, will try to do so once again.

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White House Correspondent Ben Feller contributed to this report.

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Online:

Democratic National Committee: http://www.democrats.org/

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