Democratic presidential candidate Barack Obama is on the campaign trail Saturday as rival Hillary Clinton takes time off at her home in the northeastern state of New York.

Senator Obama took part in a town hall meeting in Medford, in the northwest state of Oregon Saturday, a day after winning a key endorsement in the bid to become the party's presidential nominee.

New Mexico Governor Bill Richardson, who sought to become the nation's first Hispanic president, called Senator Obama "an extraordinary leader".

Senator Clinton's campaign had sought Richardson's endorsement. He had served in two senior positions for her husband, President Bill Clinton. Richardson is also a prominent Hispanic politician who may draw much-needed votes in a very tight race.

Clinton's campaign downplayed the endorsement saying it came too late to make a difference.

Meanwhile Senator John McCain, who is expected to win the Republican nomination, is taking time off at his Arizona home after a week-long tour of the Middle East and Europe.