President Obama sought to rekindle his 2008 message of “hope” Thursday night, promising to lead America to a “better place” if they will grant him another four years in office — and dismissing his Republican opponent as someone who is not ready for the pressures of the Oval Office.

The man who four years ago ran for the highest office in the land as a first-term senator presented himself on stage at the close of the Democratic convention in Charlotte as the experienced, battle-tested choice. No longer the upstart, Obama leveraged the power of his incumbency to make his own case, as he and Mitt Romney now dive into the general election race.

“I recognize that times have changed since I first spoke to this convention. The times have changed — and so have I,” Obama said, after formally accepting the party’s nomination. “I’m no longer just a candidate. I’m the president.”

Obama — who, like Romney, will campaign in New Hampshire and Iowa on Friday — urged his 2008 supporters not to lose faith. He cautioned that the vision of “hope” and “change” would only fizzle if they vote him out of office.

“If you turn away now, if you buy into the cynicism that the change we fought for isn’t possible … well, change will not happen,” Obama said. “If you give up on the idea that your voice can make a difference, then other voices will fill the void. ... Only you can make sure that doesn’t happen.”

The president stressed that he still has the “hope.”

“As I stand here tonight, I have never been more hopeful about America. Not because I think I have all the answers. Not because I’m naive about the magnitude of our challenges,” he said. “I’m hopeful because of you … If you share that hope with me, I ask you tonight for your vote.”

The crowd erupted in cheers as Obama was joined onstage by his family, as well as the vice president and his family, at the end of the address and the trademark convention confetti rained down on the crowd. Vice President Biden spoke before Obama, as he accepted the nomination to be the Democratic running mate.

The meat of Obama’s speech was heavy on policy, as he laid out a series of specific goals for a second term — like recruiting 100,000 math and science teachers, cutting tuition growth in half, and cutting the deficit by $4 trillion over the next 10 years.

Obama made a similar set of goals and pledges in his 2008 address, and several of them have not been met. Romney’s campaign, in a brief statement reacting to Obama’s speech, knocked the latest goals as more empty rhetoric.

“Tonight President Obama laid out the choice in this election, making the case for more of the same policies that haven't worked for the past four years,” Romney campaign manager Matt Rhoades said in a written statement. “He offered more promises, but he hasn’t kept the promises he made four years ago. Americans will hold President Obama accountable for his record – they know they’re not better off and that it’s time to change direction. Mitt Romney and Paul Ryan will restore America’s promise and deliver a better future for our country.”

Obama, though, pointedly described Romney as not ready for the job of commander in chief. He mocked the Republican candidate for his gaffe on a recent foreign trip in which he questioned London’s preparations for the Olympic Games.

“You might not be ready for diplomacy with Beijing if you can’t visit the Olympics without insulting our closest ally,” the president said.

Obama stressed the myriad security threats facing the country and said, “you can choose leadership that has been tested and proven.” He cited on his resume, as Biden did, the decision to take down Usama bin Laden.

“My opponent and his running mate are new to foreign policy,” Obama said, “but from all that we’ve seen and heard, they want to take us back to an era of blustering and blundering that cost America so dearly.”

Though heavy on foreign policy in his speech, Obama spent quite a bit of time during the address talking the economy and budget. He slammed Republicans for wanting to extend all the Bush-era tax rates — Obama wants to let them expire for top-earners — and for their budget plans, including one to turn Medicare into what Democrats call a “voucher” system. He accused Republicans of “sticking it to the middle class” with their deficit-reduction blueprint.

The address helps set the stage for the general election battle, which will play out at a furious pace over the next two months in battleground state campaign swings, national debates and the rapid-fire volley of political ads funded by the campaigns and the well-funded groups like super PACs supporting them.

Neither campaign is taking a breather after back-to-back conventions. The Obama and Romney teams are charging out of the nomination ceremonies on Friday with dueling events in the small swing state of New Hampshire. Obama and Biden are set to campaign in Portsmouth, while Mitt Romney campaigns in Nashua.

Regardless of any “bump” either candidate might enjoy out of the conventions, the election is expected to be close and hard-fought. The match-up has been airtight for months, with polls showing many voters disappointed by the state of the economy but unsure whether to back Romney as the alternative.

Obama, who said Thursday his message of hope “has been tested” by the economic crisis and other challenges, said voters face “the clearest choice of any time in a generation” at the ballots in November.

The president asked voters for more time.

“I won’t pretend the path I’m offering is quick or easy. I never have. You didn’t elect me to tell you what you wanted to hear. You elected me to tell you the truth. And the truth is, it will take more than a few years for us to solve challenges that have built up over decades,” he said.

“It will require common effort, shared responsibility, and the kind of bold, persistent experimentation that Franklin Roosevelt pursued during the only crisis worse than this one. … But know this, America: Our problems can be solved. Our challenges can be met. The path we offer may be harder, but it leads to a better place.”

The setting for Thursday’s Obama nomination address was less grand than his nomination address in 2008. That speech was held in the Denver Broncos’ stadium in Colorado and had the former senator speaking with a backdrop of stately columns.

This year, Obama was originally planning to speak at another outdoor area: the Bank of America Stadium in Charlotte. But concern about heavy rain and lightning, the campaign said, forced them to make a last-minute decision to move the nomination address indoors to the smaller Time Warner Cable Arena, where the rest of the convention was held. The decision left out thousands of ticket-holders, as the campaign urged them to stay home for the convention’s final night.

Over the course of the Democratic convention, speaker after high-powered speaker made the case for why Obama deserves another four years. They touted achievements like the federal health care overhaul, the auto bailout, the “don’t ask, don’t tell” repeal, and the take-down of bin Laden.

The endorsements followed a weeklong bashing of the Obama administration by Republicans at their convention in Tampa, Fla. Romney, as his central argument, claimed that the White House cannot claim the country is better off today than it was four years ago.