Sen. Barack Obama, coming off a rough two weeks dominated by the furor over his former pastor's anti-American comments, said he planned to compete hard in the Pennsylvania Democratic presidential primary - by treating it like Iowa.

"Hopefully, I'm going to be able to go back to that style of meeting people one-on-one and in small groups, having conversations," Obama said in an interview with The Inquirer late Friday. "That approach works well for me."

With just more than four weeks to go until the state's April 22 primary, the Democratic race has entered its longest lull since Iowa's first-in-the-nation caucuses Jan. 3, which Obama won. He was on a 11-state winning streak until Sen. Hillary Rodham Clinton won the popular vote in Ohio and Texas this this month. He still has more delegates.

Recent polls show Clinton leading in Pennsylvania by at least 15 percentage points, with strong support from women and white working-class men, key groups in her winning coalitions elsewhere.

"She's the odds-on favorite," Obama said, adding that he has not been fully introduced to the state. His campaign began television advertisements on Friday, including a biographical spot that stresses his community-organizing career.

"We've done well in states where people know that I got my start working alongside steelworkers in Chicago whose plants had closed," Obama said. "People in Pennsylvania can relate. ... The more we focus on that, the better we're going to do."

Obama had been on the defensive since video surfaced of the Rev. Jeremiah A. Wright Jr., his spiritual mentor, preaching that the United States was racist and genocidal. Wright said the federal government invented the AIDs virus to wipe out minorities, said African Americans should sing "God damn America," and called the country the "U.S. of KKK A."

Last week, Obama gave a speech on race in Philadelphia in which he condemned Wright's beliefs but asked white Americans to understand the sense of grievance in the black community that gives rise to such comments. He also asked black Americans to understand the frustration of white working-class people.

He spoke of his own white grandmother, who helped raise him, yet "once confessed her fear of black men who passed by her on the street, and ... on more than one occasion has uttered racial or ethnic stereotypes that made me cringe."

Critics said that Obama was wrong to give the same moral weight to his grandmother's fears and Wright's rants, and he appeared to compound the problem by explaining on WIP-AM (610) Wednesday that his grandmother was a "typical white person."

Obama said that he mentioned his grandmother, who lives in his native Hawaii, only to illustrate that racial fears are embedded deeply in society. He said he has spoken to her about the speech.

"She thought it was a powerful speech - but she is biased, she's my grandmother," Obama told The Inquirer.

"I have written about this in my first book, so it's not something out of the blue," he said. His description "reflects comments from 30 years ago," Obama said. "She's changed. People change."

On Friday, Obama was endorsed by New Mexico Gov. Bill Richardson, a former presidential candidate who served in the Clinton administration. Richardson expressed concern about the contest's negative tenor.

Obama said that Clinton "has the right to continue to compete," but he agrees with Richardson that the campaign has turned negative - and he blames Clinton.

"She's just trying to tear me down, and that's not the kind of politics we've been about," Obama said in the interview.