CHARLOTTE — President Barack Obama will have one more major shot alone at a microphone this year to articulate his vision of America, and Democrats want to sure tens of thousands of “everyday Americans” are there, the chairman of the Democratic National Convention committee said Wednesday.

Moving the president’s acceptance speech to the open air, 74,000-seat Bank of America stadium from Time Warner Arena will allow thousands more people to participate in the convention, Steve Kerrigan said at a news conference. The convention is being held in Charlotte in early September. The president will make his acceptance speech Sept. 6 — and organizers say the stadium makes a perfect backdrop.

“The president gets two shots at a microphone by himself. One was last week at the State of the Union, and the second is Thursday night at the convention, where he really gets an opportunity to lay out his vision ... not just for the next eight weeks of the campaign but for the next four years of his presidency.

“And we want to make sure that we get as many Americans in the building as possible and then as many Americans as possible watching — whether it’s on their iPad, their network television or however they get their information,” he said.

Kerrigan made his comments on the one-year anniversary of Charlotte landing the convention. He said convention planning was going smoothly and cited a number of key changes, including shortening the convention from the traditional four days to three so there will be a day to celebrate the Carolinas, Virginia and the South. That celebration will take place on Sept. 3 at the Charlotte Motor Speedway.

No details have been released about the Labor Day event, except that it will involve families and will allow thousands of people to participate in the convention. The massive racetrack, which annually hosts the Coca-Cola 600 — a major NASCAR race — has a permanent seating capacity of about 135,000 people. The track’s infield can hold thousands more.

Kerrigan refused to speculate how many people might attend.

“We’re not going to play the numbers game,” he said. “Our hope is that we can maximize it, that we can have as many people as possible there. We’re working on the details but our hope is to use that infield in a creative way.”

That could include grass roots organizing, noting that at an event at the Denver convention four years ago, Democrats signed up 25,000 volunteers.

“We’re not going to set a number as to how many exactly we hope because it’s free and open to the public. We’re going to encourage people to come and bring their families, bring their friends, bring their kids and really be a part of what we hope to be a really special day,” he said.

He also steered away from discussing fundraising for the convention, except to say they are on track to meet their goals. Organizers are raising $37 million for the convention.

Kerrigan also declined to comment about Occupy Charlotte. On Monday, police arrested seven people and disbanded a tent city on a lawn outside the old city hall where activists had been camping since October. It came one week after a city ordinance was adopted restricting political demonstrations ahead of this year’s convention.

The new rules approved by Charlotte City Council give police more power to stop and search people when the convention comes to town in September.

But the major part of the ordinance outlaws camping on city property.