CHARLOTTE, N.C. -- Four years after a convention in Denver that was a celebration of the candidate of "hope and change," President Obama faces a far more daunting task as he attempts to sway skeptical independents that he has done enough with his opportunities to deserve to have his contract renewed.

The euphoria surrounding Obama's historic presidential nomination four years ago has been replaced with a sobering dose of stark economic reality in an election that will center on jobs.

Rather than playing motivational speaker, Obama now becomes a salesman who must convince voters of tangible progress under his watch -- a tougher assignment than the vow to transform politics that paved his last run to the White House.

Here is what Obama needs to accomplish during the Democratic gathering in North Carolina just two months before the election.

• Answer the "are you better off" question

With the country's unemployment at 8.3 percent, gas prices at $4 a gallon, and the national debt exploding by $5 trillion to more than $16 trillion during Obama's term, the GOP wants voters to ask if they are better off under the president's leadership. Yet, the Obama campaign has already hinted that speakers would focus on how GOP nominee Mitt Romney would adopt so-called Bush economics. The president faces a delicate balancing act in evoking memories of President George W. Bush without looking more focused on blaming his predecessor than leading. "The president has to remind people where we've come from and that if they elect the Romney-Ryan ticket, we're doomed to repeat the mistakes of those eight years," said Democratic strategist Karl Frisch.

• Sell Obamacare

As his signature achievement, Obama needs to credibly sell his health care overhaul to a public wary of the costs and implications of the sweeping change. A litany of speakers are lined up to tout the notion that Obama, as an advocate of universal health care coverage, is more sympathetic to the needs of middle-class Americans than Romney. Obama can be expected to focus on medical perks rather than the expected bill for taxpayers. The latest Gallup poll on Obamacare found that a majority believed the law would benefit those who get sick -- but 60 percent said the reforms would "make things worse" for taxpayers.

• Frame Romney as unelectable

The theme of the Republican National Convention in Tampa, Fla., last week was that Romney could be trusted in the White House. Now it's up to Obama -- and his surrogates throughout the week -- to take a sledgehammer to that image. Convention viewers should expect a heavy helping of programming devoted to Romney's past business dealings, his tax returns and any kind of detail that could make the wealthy businessman look out of touch with most Americans. But some analysts warned that such a strategy could backfire. "It's not going to be enough for the incumbent just to bash the challenger; the bashing has seemed to reach a saturation point," said Susan MacManus, a political scientist at the University of South Florida.

• Win over Bubba voters

It's no secret that white, working-class voters are Obama's biggest liability to winning re-election. As such, President Bill Clinton -- a folk hero among Blue Dog Democrats -- will formally nominate Obama on Wednesday. Obama needs to convince these crucial swing voters that the budget authored by GOP vice presidential candidate Paul Ryan and embraced by Romney would disproportionately favor the wealthy at the expense of the working class. Doing so is the pathway to victory in swing states such as Ohio and Virginia.

• Define his vision of America's role on the foreign stage

The killing of Osama bin Laden easily ranks as one of the signature achievements of the Obama administration. But many still believe the president lacks a clear vision on foreign policy. Liberals ask why Guantanamo Bay remains open and why the president escalated the war in Afghanistan. Others wonder why Obama has stood silent in the face of the massacre of civilians in Syria.

Though the election will center on the state of the economy, Obama must prove he can handle his commander in chief duties.