(CBS) -- Boxing sensation Manny "Pacman" Pacquiao has done it all in the ring, winning world championships in seven different weight divisions.

He'll go for an eighth title next week, but as he tells Bob Simon, his main concern right now is politics - he also won election to the Congress of the Philippines last May - a distraction his trainer believes could be hurting his chances in the upcoming bout.

Simon's profile of Pacquiao will be broadcast on "60 Minutes," Tomorrow! Sunday, November 7, at 7 p.m. ET/PT.

When Simon brings up his political career, Pacquiao lets him know that serving his fellow Filipinos is where his priorities lie now. "I already achieved my goals in boxing, my dreams in boxing," says the 31-yr.old fighter. "What I want to achieve more is in public service...I want to be a champion there," he tells Simon.

But whether he will be the World Boxing Council's Super Welterweight champion after next Saturday is what concerns his trainer, Freddie Roach. Roach thinks Pacquiao is not focused enough on beating Antonio Margarito, a taller, heavier fighter he will meet in Cowboys Stadium in Dallas before 70,000 people. "I'm worried about it. Yes, I'm walking around at two in the morning," he says. "Something is not right and we are not preparing the way we should for this fight."

Pacquiao has only lost three bouts in his professional career, which began when he was 16 fighting in the 105-lb. division. Could he lose this one? "If he keeps on the road he's going, yes," Roach tells Simon.

Pound for pound, Pacquiao is said to be the best fighter in the world. He might be the best ever, a notion he has no doubts about: "Of course, me!" he answers, when Simon asks him who is the greatest ever. His promoter, Bob Arum, says he's better than the greats he's promoted over the last 40 years, including Muhammad Ali.

"Manny Pacquiao is the best fighter that I have ever seen," Arum says.

Better than Ali? "Yes he is, because Ali was essentially a one-handed fighter. Manny Pacquiao really shocks these fighters because he hits equally hard from the left side and the right side," explains Arum.

Right now, Pacquiao is training in Los Angeles for the big fight, where he and his large entourage live in an apartment. "60 Minutes" cameras were let in to catch the champ at home.

Pacquiao will also be featured in a segment on our new Web show, "60 Minutes Overtime."