(Reuters) - President Barack Obama delivered a scaled-back pitch for another term in office on Thursday, steering clear of ambitious promises and warning voters that the next four years could hold disappointment even if he won.
It was a sharp contrast to the speech Obama delivered four years ago in Denver, when he emerged as a transformative candidate, the first African-American to win the presidential nomination of a major party.
Obama will face Republican Mitt Romney in the November 6 election, but he also will confront the lingering ghosts of his history-making 2008 bid.
Campaigning on a theme of hope and change then, Obama's re-election prospects now turn on the prosaic stream of data that, day by day, paint a portrait of an economy that is still struggling to emerge from the deepest recession since the 1930s.
"I won't pretend the path I'm offering is quick or easy," Obama said on Thursday. "It will take more than a few years for us to solve challenges that have built up over decades."
Although Obama has won significant victories in office, from a dramatic expansion of health coverage to the end of the Iraq war, voters remain preoccupied with the sluggish economy. Obama's own aides have struggled to make the case that voters are better off now than they were four years ago, and the president could be hurt by a gap between expectations and reality.
"He's been talking for four years in big ways about the future, and at some point you deplete some of that capital," said Carleton College professor Steven Schier.
Romney is hoping to win over disillusioned Obama supporters who still hold a favorable view of the president even as they give the economy low marks.
Obama, by contrast, seemed to be aiming squarely at core supporters in a speech that thrilled the 20,000 Democratic stalwarts in Charlotte.
He celebrated signature accomplishments such as the auto-industry bailout and the death of Osama bin Laden, and delivered red-meat attacks on Romney that analysts said would go a long way toward firing up those who backed him four years ago.
"The main thing he did was to inspire the Democratic base to say 'we need to have people out mobilized.' They're in trouble if they don't," said Stanford University professor Morris Fiorina.
Obama has offered few new policies since his $450 billion jobs package was rejected by congressional Republicans last year. The goals he unveiled on Thursday were modest at best.
Where he promised to create 5 million green-energy jobs in 2008, this year he called for 600,000 jobs in the natural gas industry - a pace the booming sector appears to be on a path to achieve on its own.
The one million new manufacturing jobs he would create by 2016 would not be enough to replace the 2.3 million that disappeared during the recession, and the 100,000 new math and science teaching positions he proposed would equal the number of teaching jobs that have been lost during the past year because of budget woes.
But it was not a night to talk about policy.
With nearly half of U.S. voters only dimly aware of the difference between Republicans and Democrats, most watching on TV probably were just looking for Obama to convey authority and ease - a task he accomplished handily, analysts said.
"For a lot of voters who don't want to get into the weeds on Medicare, they saw a rock star tonight," said Potomac Research Group analyst Greg Valliere.
