WASHINGTON: Sen. Barack Obama aimed to weave the personal with the political yesterday as he explained to 75,000 supporters in a football stadium — and millions more at home how as president he would make a — difference in their lives. Sen. Obama, the first black person to claim such a prize, spoke on the 45th anniversary of Martin Luther King Jr.’s historic “I Have a Dream” speech. And Sen. Obama’s exotic background -— his unique mélange of Kenya, Kansas, Hawaii and Harvard — makes the job of presentation his life story particularly important.

Pennsylvania Gov. Ed Rendell made that point bluntly in an interview with journalists this week, when he compared Obama to the brilliant Adlai Stevenson, who twice failed as the Democrats’ nominee. “With people who have a lot of gifts, it’s hard for people to identify with them,” Rendell said. “Barack Obama is handsome. He’s incredibly bright. He’s incredibly well spoken, and he’s incredibly successful — not exactly the easiest guy in the world to identify with.”

The latest Washington Post-ABC News poll confirms that fear: the number of voters who favor Sen. Obama over Sen. McCain has fallen since March. Then, 55 percent of registered voters gave Sen. Obama credit for understanding them, compared with 29 percent for McCain. Now, the gap has narrowed, with Obama at 49 percent to McCain’s 39 percent.

Obama’s strategists say Sen. Obama needs to seem more approachable to voters in a way that does not seem phony. Those that know him say Sen. Obama has long trained himself for this competition; he can sometimes seem as much athlete as politician. Even before he entered public life, they say, he began honing not only his political skills, but also his mental and emotional ones. The result is that he has established domination over not only what he does but also how he feels. He does not easily exult, despair or anger: to do so would be an indulgence, a distraction from his goals. Instead, they say, he separates himself from the moment and assesses.

But when Barack Hussein Obama officially became the Democratic presidential nominee at the Democratic National Convention, some of the same qualities that have brought him just one election away from the White House — his virtuosity, his seriousness, his ability to inspire, his seeming immunity from the strains that afflict others — may now be among his biggest obstacles in getting there. Sen. Obama’s task now is to convince voters that he understands them, but without leading them to question whether he has lost himself in the process.