EUGENE, Ore. (AP) - Scoring an endorsement of national importance, Barack Obama threw down a marker Friday in four Willamette Valley cities in the race for Oregon's suddenly important 65 delegates and their votes for the Democratic presidential nomination.

Hillary Clinton's camp responded by saying she would be in Oregon within weeks, well before primary voting starts.

After stops in Portland and Salem, plus an impromptu meet and greet in Corvallis, Obama wound up his day in Eugene, where he spoke to about 9,000 people at the University of Oregon's basketball arena, affectionately known as "The Pit."

"Wow," he said. "So this is what they call the Pit. I love you back!"

His speech in Eugene touched on the economy and alternative energy, but the biggest applause was reserved for his pledge to bring a speedy end to the war in Iraq.

"We have three candidates left running for president, and only one of them recognized that this was a bad idea from the beginning," Obama told the crowd. "We cannot wait to bring an end to this disastrous war in Iraq."

Until early primaries failed to decide the contest, it appeared that the counting of Oregon's primary ballots on May 20 would be an academic exercise.

But Obama's four-stop swing through Oregon - including a high-profile endorsement from New Mexico Gov. Bill Richardson - demonstrated that the results may be important as the two candidates try to sew up the nomination before the contest reaches the floor of the national convention this summer.

Pollster Tim Hibbitts of Portland said there are no recent, public poll results on the Obama-Clinton matchup in Oregon. He said his impression is that the race is too close to call, but Clinton is the underdog.

In Portland, Obama's message resonated with crowd members such as Brenulla White, a nutritionist.

"Obama talks about doors that have not been opened, and it's time for those doors to be opened," she said.

White said her son served two tours of duty in Iraq in the Army, and she praised Obama for promising to start bringing home the troops and for confronting racial issues.

"It's time for racial differences to come to the forefront and be resolved," she said. "How can a country fight if it's divided?"

White and another black woman at the rally said Obama can reach average people, define the issues for them and bring them together.

"I find him absolutely inspiring," said Melissa Marley, a graduate student.

In Salem, Obama drew about 3,000 people to the National Guard Armory where he spoke and took questions.

In answer to one about immigration, he dismissed the idea that the United States could return all the people who are in the country illegally.

"You couldn't do it," he said. "It would be the most expensive undertaking you could imagine."

And, he said, it would damage the nation's reputation in the world. "That's not who we are," he said.

If undocumented workers acknowledge that they have broken the law and pay fines and back taxes, Obama said, "then there should be a pathway so that over time they can earn their citizenship and have legal status."

The endorsement from Richardson, the nation's only Hispanic governor, probably has more influence in states other than Oregon, where the Hispanic vote is regarded as small and not a factor in the primary or general election, said Hibbitts, the Portland pollster.

Clinton, he said, should be worried about independents who are registering as Democrats to vote for Obama in the primary. He said the switch could amount to between 20,000 and 40,000 voters, based on his conversations with various counties.

The Clinton campaign said it would not make a perfunctory effort in Oregon. "Both Sen. Clinton and President Clinton will be campaigning in Oregon," said Isaac Baker, campaign spokesman for Hillary Clinton. "We're going to run a very aggressive campaign."

Obama planned stops later Friday in Eugene and on Saturday morning in Medford.

Oregon voting starts in early May.

The candidates will divide 52 pledged delegates in proportion to their primary vote totals. Twelve more so-called superdelegates, party leaders and officials, will go to the national convention without being formally committed. One more delegate to the national convention is to be chosen at the party's state convention in June.

(Copyright 2008 by The Associated Press. All Rights Reserved.)