Updated

College students from across North Carolina will arrive in Charlotte by the busload. Same with members of predominantly black churches in neighboring South Carolina.

Their goal: help fill a 74,000-seat outdoor stadium to capacity when President Obama accepts the Democratic nomination Thursday night.

Anything short of a full house on the final night of the Democratic Party's national convention will be instant fodder for Republicans eager to use empty seats as symbols of waning voter enthusiasm for Obama.

Democrats have been fretting for months over whether the president can draw a capacity crowd at Bank of America Stadium. Polls show voter enthusiasm is down, as are Obama's crowds for his battleground state campaign rallies.

Obama advisers insist the stadium will be filled when Obama delivers his speech. Vice President Joe Biden also will speak Thursday night, along with Massachusetts Sen. John Kerry, who will vouch for Obama's national security credentials.

"The response we've seen from the community has been incredible and it's obvious that people have a big interest in owning a piece of the most open and accessible convention in history," said Adam Fetcher, a campaign spokesman. "President Obama's speech on Thursday night will bring this election into focus for the American people, and it will be even more significant because so many North Carolinians will be there to see it."

Convention delegates, volunteers and other Democratic officials already in Charlotte for the party gathering could make up as much as one-third of the crowd. But filling the rest of the stadium is a piecemeal process.

Elena Botella, a student at Duke University and president of the College Democrats of North Carolina, said her school was busing 100 students to the speech.

Lonnie Randolph, the president of the South Carolina chapter of the NAACP, said several large black churches in his state are planning to send busloads of members on Thursday to watch the president's speech.

"There are plenty of people who wouldn't miss it for the world," Randolph said. "How often does this happen this close to South Carolina?"

Obama aides say several thousand tickets also have been given to new campaign volunteers in North Carolina. People who complete three volunteer shifts totaling nine hours got one ticket to the final speech.

The volunteer ticketing program also helps Obama boost his grassroots network in North Carolina, a battleground state he moved into the Democratic column in 2008 for the first time in nearly 40 years. But Obama is facing an uphill battle this time around in North Carolina, where the unemployment rate exceeds the national average and voters approved a gay marriage ban the day before the president announced his support for same-sex unions.

Thursday's event is certain to draw comparisons to 2008, when Obama accepted the Democratic nomination before a capacity crowd at an 84,000-seat stadium in Denver. There was little concern back then over whether Obama would fill the stadium, in part because he was easily attracting tens of thousands of people to his campaign rallies across the country.

This time around, Obama's crowds are far smaller. He drew his biggest audience at his campaign kick-off rally in May, a 14,000-person crowd at Ohio State University. About 13,000 people attended Obama's rally at the University of Colorado in Boulder Sunday.

The campaign says the size of Obama's events this summer have purposely been kept low. Large rallies are more expensive and security requirements are more intense for a sitting president than a candidate.

Convention organizers in Charlotte may have more control over the crowds than their other big concern: the weather. Heavy evening rains doused Charlotte over the weekend, and thunderstorms are in the forecast for Thursday.

Officials say the outdoor event will go on rain or shine, except if there is severe weather.