RAPID CITY - Presidential hopeful Barack Obama asked South Dakota voters Saturday to give him a boost in the state's upcoming primary, as his long battle with rival Hillary Rodham Clinton nears an end.

Speaking to about 2,700 people during a town hall meeting at the county fairgrounds in Rapid City, Obama said he wants to be president because he believes the nation's policies at home and abroad need to be changed now.

"You and I together, we're going to change the country, we're going to change the world," the Illinois senator said.

South Dakota and Montana hold the nation's last presidential primaries on Tuesday.

Obama holds an almost insurmountable lead in delegates over Clinton, and the Democratic nomination is expected to be decided in the next week as party leaders called superdelegates commit to either Obama or Clinton.

In a 25-minute speech followed by a question-and-answer period, Obama mentioned issues important to American Indians and military veterans.

About 8 percent of South Dakota's population is Indian, and Ellsworth Air Force Base sits just a few miles from where Obama spoke on Saturday.

Clinton and her husband, former President Bill Clinton, have made multiple campaign appearances on South Dakota's Indian reservations over the past few weeks, but Obama has not appeared in Indian Country.

However, the Democrat was introduced Saturday by Ida Fast Wolf, a member of the Oglala Sioux Tribe who lives in Rapid City.

Fast Wolf said she taught eighth grade on the Pine Ridge Indian Reservation this past school year, but the rising price of gas means she will no longer be able to do so next year.

"The reason I support Senator Obama for president is I know in my heart he will fight for people like you and me, regular people," she said.

Obama said the Democratic Party will unite to win the White House in November, despite the lengthy nomination fight.

"We are going to come together, because Senator Clinton is an outstanding public servant. She has run a magnificent race," Obama said. "She is going to be working on behalf of the Democratic party, as I will be."

Obama paid particular attention Saturday to plans for developing alternative fuel sources, including the promotion of solar and wind power and the manufacturing of biodiesel. He said those industries can create millions of jobs in places such as South Dakota.

He also called for providing high quality, affordable health care for everyone, especialy military veterans.

Obama said he believes Americans are tired of old-fashioned politics.

"Most of all, I believe the American people are tired of being divided. They want to come together - black, white, Hispanic, Asian, Native American, young, old, male, female," Obama said to a standing ovation.

He also draw loud cheers when declaring that changes have to be made to President Bush's "No Child Left Behind" education policies.

Mary Borella, of Rapid City, attended the event with her daughter Amy, son-in-law Josh Precht and her granddaughter.

Borella said she's for Obama because he's intelligent and seems less political than other candidates.

"I'm here to see the next president," Borella said. "I think we're going to have a change with him."

Precht and his wife said they remain undecided and are still comparing Obama and Democrat Hillary Rodham Clinton.

"This is my last chance, I guess, to make up my mind," Precht said.

Earl Jefferson, of Rapid City, who is retired from the U.S. Air Force, said he has supported Obama for a long time.

Jefferson said as a black man, he was following Obama's career even before he became a national political figure. He said it was apparent that Obama was capable of good things.

"I'm a Barack Barack Barack fan," he said.

Jefferson he's been telling all his friends to support Obama.

"I really think he's going to win this state," he said.

Precht said South Dakota is lucky to get so many visits from the Democratic presidential candidates as the state and Montana have the nation's last primaries.

"I just think it's neat to get this kind of attention in South Dakota. Otherwise we'd never get this opportunity," he said.

Jeff and Cindy Bailie are registered Republicans but attended the event because it presented a good opportunity to hear a candidate in person.

Both said South Dakotans are getting a great chance to hear the Democratic candidates.

"I think it's democracy in action," Jeff Bailie said. "I think it's a tremendous opportunity to come out and listen to a man who might potentially be the next president of our nation."

Gordon Bryan, of Rapid City, said he is a "dyed-in-the-wool Republican" but came to see what Obama would say.

"You need to know what the competition is up to," Bryan said.

His wife, Elizabeth Bryan, an Episcopal priest, said she is a devoted Democrat and has also attended rallies featuring Hillary Rodham Clinton and Bill Clinton.

"We have this rare opportunity. Grab it," she said.

On Sunday morning, Obama will appear at a private event for veterans in Sioux Falls before heading to Mitchell for a campaign rally at the Corn Palace.