A rising star from Illinois makes some noise in L.A.

Barack Obama was telling a story about campaigning for the Senate in Illinois two years ago. He was on a road trip with Dick Durbin, the state’s senior senator, he explained. They were traveling in downstate Illinois -- far away from Obama’s home base of Chicago.

Obama paused before a rapt crowd at the California African American Museum in Exposition Park to deliver an aside: “And southern Illinois is the South.”

“HEL-lo!” history professor Wanda Powell rang out in agreement.

“One place we went to was a place called Cairo, Ill.,” Obama continued.

“The reason why everybody remembers Cairo is because back in the late ‘60s and early ‘70s, Cairo was the site of some of the worst racial violence.”

That story ended with Obama and Durbin spotting people in Cairo sporting Obama buttons and ready to fete the candidate with barbecue.

But everyone at the museum already knew how the bigger story unfolded: Democrat Barack Obama -- the son of a black father from Kenya and a white mother from Kansas, as he fondly recited several times Friday -- electrified the 2004 Democratic National Convention as a speaker, won his Senate race and in two short years catapulted from junior senator to fantasy presidential candidate and Time magazine cover guy.

“We brought students here,” said Powell, a history professor at Los Angeles Southwest College. “This is a historic moment.”

Obama swung through Los Angeles on Friday, speaking to a crowd of 825 at the museum. Then -- with actor Ben Affleck -- he promoted Proposition 87 at a news conference at USC’s Topping Student Center. Later in the afternoon he delivered a 14-minute speech in shirt sleeves at a campus rally with Democratic gubernatorial candidate Phil Angelides, Los Angeles Mayor Antonio Villaraigosa and just about every other California Democratic office holder who could find their way to USC.

People came to the day’s events clutching copies of Obama’s new book, their cameras and their hopes that he is the political force that can unify a divided country.

“We live in Orange County. We live behind the Orange Curtain,” said Jona Knight, a human resources manager, as she waited in line to have her copy of Obama’s “The Audacity of Hope” signed. “I’ll get his signature on this book. I’ll give this book to my grandchildren.”

She came with her friend, Pamela Reeves, a paralegal and psychotherapist intern, who said: “It’s not just blacks or African Americans -- there are a lot of people that feel like they can have a connection with this guy.”

Even members of the on-campus chapter of the College Republicans, standing at the back of the Democratic rally with their Schwarzenegger signs, were diplomatic: “I’m not really on point with his views, but he’s definitely a popular man,” said Cheyenne Steel, a 19-year-old sophomore.

At the museum speech and book signing, sponsored by Eso Won Books and the Urban Issues Forum, Obama signed every volume. As though on an assembly line, people walked by, proffered a book -- and Obama, a left-hander who curls his fingers around the pen, flicked out his signature: a big B joined with a big O and a line shooting out from there.

Younger members of the museum crowd wanted him to go with the momentum and run for president in 2008. Older fans counseled caution. “He needs some more seasoning -- then there’ll be time to run for president,” said Quincy Beaver, 84, president of the Martin Luther King Jr. Democratic Club.

Some fretted like worried mothers: “I don’t trust the powers-that-be not to have other plans for him,” said Valaria Lincoln, 72. “I’m afraid for him.”

There were no fears among the students who besieged Obama at USC, wearing Democratic buttons and hoisting cellphone cameras aloft to click him and Affleck as they spoke on behalf of Proposition 87, the Clean Alternative Energy Act.

“He has already proven himself to be the most galvanizing leader to come out of either party, in my opinion, in at least a decade,” said Affleck, wearing an untucked blue shirt and gray trousers as he introduced Obama, who was in a white shirt and dark suit jacket and went tie-less all day. “

Obama reminded the audience that the proposition is opposed by the “big boys,” meaning the oil companies. And he spoke of the overdependence on foreign oil. “We’re sending $800 million a day to some of the most hostile nations and effectively funding both sides in the war on terror.”

“It was nice to have Ben Affleck there,” said Alexander Shams, a 16-year-old freshman, “but Barack Obama was the star.”

At the rally for the Democratic Party in front of a flag-draped Doheny Library, Obama spoke last, after Villaraigosa and Angelides. Under a cloudless sky and bright sun, before hundreds, Obama removed his suit jacket and rolled up his shirt sleeves -- a stark contrast to the dark-suited, buttoned-up politicians around him.

“How you doing, USC?” he called out as the crowd roared in delight. “I’m fired up. I’m so fired up I had to take off my jacket.”

Once more he went over his message: “We’re all connected. We have a stake in each other,” he said, “despite our much-vaunted individualism.”

He continued: “There’s just one ingredient it’s going to take to make it happen on Nov. 7,” he said. “That’s all of you.”

Then he managed to segue from Martin Luther King Jr.’s entreaty to his followers in the early days of the Selma marches -- not to give up but to stand together -- to Angelides (trailing the governor in double digits) and to how all Democrats standing with him would be a powerful force.

Then he was sent off with a crescendo of applause.

carla.hall@latimes.com