Obama lightens up after a good week

By Deborah Charles

CHICAGO (Reuters) - What a difference a good week makes.

Ever since he strengthened his lead in the Democratic race for the White House last week, Barack Obama looks like a weight has been lifted off his shoulders.

In his first days back on the campaign trail since a decisive victory in North Carolina, the Illinois senator has joined in on games with reporters he has snapped at in the past, pretended to run a hurdle event at a college track meet and been surrounded at a taco shop by diners cheering him on in Spanish.

A week ago, Obama was wondering if he would lose votes after some stumbles while campaigning and after being forced to denounce his former pastor.

But he looked like he had few worries this week as he moved closer to a victory over rival Hillary Clinton for the Democratic Party's nomination and the right to face Republican John McCain in November's U.S. presidential election.

Obama received a standing ovation from about 5,000 fans then walked a victory lap around the track during a surprise visit to the Twilight Track Meet at the University of Oregon on Friday.

He grinned widely as he walked around shaking hands, posing for pictures and throwing bright yellow T-shirts into the stands. He even pretended to take up the announcer's invitation to join the men's 400-metre hurdles race.

"Excellent form" the track announcer said over the loudspeaker after Obama -- in dress shoes and slacks -- jogged up to a hurdle then stopped and stepped over it, jogged a few steps and then stopped and waved to the cheering crowd.