Facing a tight race against Republican presidential nominee Mitt Romney, US President Barack Obama is preparing to convince disappointed voters he can do better at boosting the US economy than he has the past four years, when he appears at the upcoming Democratic National Convention this week.

A Reuters/Ipsos poll found on Sunday that the two opponents are tied in the presidential race, with 45 percent for Obama and 45 percent for Romney, a former Massachusetts governor, among likely voters.

US President Barack Obama poses for a picture with customer Barbara McCluskey at The Buff Restaurant while campaigning in Boulder, Colorado, on Sunday. [Photo/Agencies]

Obama still enjoys a slight advantage among registered voters, with 47 percent compared with Romney's 46 percent in Gallup's latest poll.

Coming on the heels of the GOP's convention in Tampa, Florida, the Democrats are preparing for a different gathering in the battleground state of North Carolina, with what the party claims will have a larger and more diversified participation than the Republicans' convention. It is the first political convention in the southeastern US in 24 years.

Convention week was scheduled to kick off on Monday, with CarolinaFest in the convention's host city of Charlotte, and it will close with the acceptance speeches of Obama and Vice-President Joe Biden at the 74,000-seat Bank of America Stadium.

The Democratic Party is sending about 6,000 super delegates, delegates and alternates to the "Queen City," up from 4,419 delegates in 2008.

The vast majority of each state's delegates will be "everyday Americans who are energized and passionate about participating in the democratic process", according to the convention website.

The headline speakers will include San Antonio, Texas, Mayor Julian Castro; first lady Michelle Obama; US Senate candidate Elizabeth Warren from Massachusetts; and former president Bill Clinton.

Obama's Thursday night speech is highly anticipated because of the expected announcement of his plans for the next term.

In 2004, Obama, then a young senator from Illinois, gave a passionate keynote speech at the Democratic convention in support of John Kerry. In the 2008 convention, his speech was equally inspirational after Obama became the Democratic presidential nominee himself.

But it is widely believed that the kind of enthusiasm Obama enjoyed among his supporters in 2008 may wane in this year's election, largely because of frustration with the president over the past three years, including his failure to raise taxes on the rich, and his approval of drone attacks in Pakistan and Afghanistan.

Whether Obama can use this week's convention to advance his narrow lead against Romney is still in doubt.

One bad omen was a Sunday protest in downtown Charlotte by an estimated 800 to 1,000 people outside big corporations such as Bank of American and Duke Energy. Protesters called for more protection for the poor and unemployed, and for less influence of corporations and money in politics.

Although Obama leads Romney in likability among the American public, he trails Romney in the public's perception of his ability to handle the economy. Jobs and economy have been regarded as the single most important topic of the 2012 election.

Obama has accused Romney's economic plan, such as favoring oil companies over renewable energy, of lacking a vision for the future. But under a persistent unemployment rate of more than 8 percent, a national debt in excess of $15 trillion and increasing pessimism among the public, Obama must convince the American public why his economic policy is better than Romney's.

Analysts also expect Obama to make a case that Romney's success at private equity firm Bain Capital led to suffering of the weak and vulnerable, and that the experience there is totally different from running a government.

In 2008, Obama won North Carolina by the smallest margin among all the states he won. Analysts believe winning such a swing state will have huge significance in boosting the much-needed morale among the Democratic base.

Contact the writers at tanyingzi@chinadaily.com.cn and chenweihua@chinadaily.com.cn