The U.S. Democrats launched their case for President Barack Obama’s re-election at his nominating convention Tuesday, looking to draw a sharp contrast with Republican rival Mitt Romney and convince voters that Obama has the more sensible plan for economic recovery.

HE’S older. He’s greyer. The jaunty optimism about changing the world has given way to the sober reality of stubbornly high unemployment and economic anxiety. In his own words, U.S. President Barack Obama has “some dents and dings in the fender.”

Yet beneath those external differences, the question persists: How has Obama changed as a leader in the four years since he first accepted his party’s nomination for president as a young man with little executive experience and little history in Washington. Has he learned on the job? Has he been guided by core principles come what may, or has he changed to adapt to what’s become a vastly different political landscape? The answers could determine how successful he’d be in a second term.

Obama enters the home stretch of his re-election campaign amid a still-struggling economy, with national polls showing him virtually tied with Republican challenger Mitt Romney.

But Obama has one big thing going for him: voters seem very much to like him personally, and many remain loyal to him even as they give him low marks for his handling of the economy.

If his campaign team can convince his 2008 supporters to flood back to the polls this November, while also persuading undecided voters that Romney does not have their interests at heart, he will win a second term.

Obama, America’s first black president, has had a turbulent first term in office.

He and his fellow Democrats scored several historic achievements. But the U.S. economy has struggled mightily since Obama took office amid one of the worst economic recessions in decades: job growth has been anemic and the U.S. unemployment rate has remained over 8 percent.

Add to that, the Democratic Party suffered historic losses in the mid-term polls in November 2010, with the Republicans emerging energized and more determined than ever to promote their conservative agenda and stymie the president’s plans.

Romney and the Republicans are now betting that Obama will be unable to inspire the same enthusiasm that carried him to the White House and that independent voters will turn away from his policies amid a still-lagging economy.

Since Obama took office in 2008, the Democrats overcame Republicans’ united opposition to pass an economic stimulus program, overhaul the U.S. health care system, lay down new rules for Wall Street and the banking industry, and rescue the U.S. auto industry from collapse.

Later, he and the Democrats overturned a two-decade-old law banning openly gay Americans from serving in the U.S. military. Wielding his presidential authority, Obama also acted without the consent of Congress to grant temporary legal status to some young illegal immigrants brought to the United States as children.

Obama dispatched a team of commandos to kill Osama Bin Laden, oversaw the conclusion of the U.S. war in Iraq and struck a new nuclear arms treaty with former Russian President Dmitry Medvedev.

Early in his presidency he escalated the U.S.-led war in Afghanistan, and the United States has seen a consequent rise in violence there. But Obama has pledged to turn the security mission in Afghanistan over to Afghan troops by the end of 2014, thus ending the more than a decade-long conflict.

“On the one hand, he’s got a legacy,” said George Edwards, a scholar of the presidency at Texas A&M University, pointing to sweeping financial regulations and health care legislation sought by Democrats for decades. But Obama also displayed what Edwards called a “misunderstanding of leadership,” which put too much emphasis on his own powers of persuasion and led Obama to “overreach” on health care.

“As a result, he lost the ability to govern because he lost Congress and he’s not likely to get Congress back. Ever,” Edwards said.

To Obama and his inner circle, his steadiness is a critical virtue.

He remains “the most steady, unflappable member of the entire team,” in the words of former White House aide Bill Burton.

“The traits that made him a good candidate, make him a good president,” said Burton, who left the White House in 2011 and is a senior strategist with a pro-Obama “super” PAC, Priorities USA Action.

First lady Michelle Obama’s emotional speech Tuesday night at the Democratic convention gave the audience just what they wanted: a reason to fall in love with Barack Obama all over again, nearly four years into a presidency that has left him somewhat battered.

In a speech well received by a hyped-up crowd, she shared memories from their 23-year relationship, and noted that she had found a “kindred spirit” in a man whose values were similar to hers.

“Barack and I were both raised by families who didn’t have much in the way of money or material possessions but who had given us something far more valuable — their unconditional love, their unflinching sacrifice, and the chance to go places they had never imagined for themselves.”

She added: “Barack knows what it means when a family struggles. He knows what it means to want something more for your kids and grandkids.

“Barack knows the American Dream because he’s lived it… and he wants everyone in this country to have that same opportunity, no matter who we are, or where we’re from, or what we look like, or who we love.”

She said Obama was inspired by his own background when advocating for laws involving fair pay for women, health care and student debt.

He had not been changed by the White House, she said: “He’s the same man who started his career by turning down high-paying jobs and instead working in struggling neighborhoods where a steel plant had shut down, fighting to rebuild those communities.”

In the toughest moments, she added, “he just keeps getting up and moving forward… with patience and wisdom, and courage and grace.”

In a speech that rocked the Democratic National Convention, former President Bill Clinton proclaimed Wednesday night, “I know we’re coming back” from the worst economic mess in generations and appealed to hard-pressed Americans to stick with Obama for a second term in the White House.

Clinton, conceding that many struggling in a slow-recovery economy don’t yet feel improvement, said circumstances are indeed getting better, “and if you’ll renew the president’s contract you will feel it.”

Obama, he said, should not be blamed for the poor economy he inherited in 2009 and has set the foundations for strong growth, if voters give him more time and re-elect him Nov. 6.

“Listen to me now,” said Clinton. “No president — not me, not any of my predecessors — could have fully repaired all the damage that he found in just four years.”

Obama’s top political adviser, David Axelrod, argues that Obama has discovered his own way to advance his agenda. For months, he’s elected to take his case directly to the public, traveling to swing states and urging crowds at campaign-style events to call, e-mail, fax or tweet their members of Congress.

“He’s learned that in this political environment, the way to move things through an entirely implacable Congress is to engage the American people in that discussion,” said Axelrod, who maintains that Republican lawmakers wouldn’t have agreed to extend the payroll tax last winter if Obama hadn’t traveled to swing states and made his case.

“Whether the day is going well or going badly, he’s focused,” Axelrod said. “Given the times we’ve gone through, two wars and a once-in-a-century economic and financial crisis, that quality of solidity and unflappability is incredibly important.”(SD-Agencies)