Hillary Clinton scored a blowout victory in the Kentucky Democratic primary Tuesday, hours before Barack Obama confidently claimed a majority of pledged delegates for the Democratic nomination with a win in Oregon.

Obama was winning by about 16 points with 86 percent of the votes in, in Oregon's all mail-in primary.

The Obama campaign quickly calculated Tuesday evening that it had achieved what it called a critical "milestone" in Obama's seemingly inexorable march toward the nomination. With the expected results from Oregon, Obama has a majority of the pledged delegates, but not a majority among all delegates.

Obama will still be 60-70 delegates short of a majority among all delegates to the convention -- both the pledged and the unpledged superdelegates  -- when Oregon votes are fully counted.

The Democratic front-runner claimed Tuesday night at a rally in Des Moines, Iowa, that he had captured most of the pledged delegates at stake in the 56 Democratic contests.

"We have returned to Iowa with a majority of delegates elected by the American people, and you have put us within reach of the Democratic nomination for president of the United States," Obama declared at the site of his Jan. 3 caucus triumph.

His decision to hold his primary-night rally in a state the campaign considers important to Democrats in November was a sign that Obama is looking straight ahead to the general election.

In his address, he attempted to reach out to Clinton and urge Democrats to unite against presumptive GOP nominee John McCain.

"We've had our disagreements during this campaign, but we all admire her courage, and her commitment and her perseverance," Obama said of Clinton. "And no matter how this primary ends, Senator Clinton has shattered myths and broken barriers and changed the America in which my daughters and your daughters will come of age. And for that we are grateful to her."

The campaign claimed the pledged-delegate milestone earlier in an e-mail to supporters, as his aides touted the achievement.

"I don't think anybody has ever won the majority of pledged delegates and have not been the nominee of the party, so it's obviously very important, but we are going to fight for every delegate and finish out the process," Obama strategist David Axelrod told reporters.

But Clinton won the Kentucky primary by a better than 2-to-1 margin. The win comes one week after Clinton trounced Obama by 41 points in West Virginia, exposing the Democratic front-runner's weaknesses among whites, working-class voters and other groups.

"Tonight we've achieved an important victory," Clinton told an enthusiastic crowd at her victory rally earlier in Louisville, Ky. "It's not just Kentucky bluegrass that's music to my ears, it's the sound of your overwhelming vote of confidence, even in the face of some pretty tough odds."

With 100 percent of precincts reporting in Kentucky, Clinton won 65-30 percent.

Seventy-one percent of white voters, 78 percent of seniors and 68 percent of voters without college degrees went for Clinton in Kentucky, according to FOX News exit polls.

The exit polls showed that 64 percent of Clinton voters still think she will win the Democratic nomination.

Click here to see photos from the Kentucky and Oregon primaries.

Clinton's performance Tuesday -- and its campaign financing haul for the month of April -- gave the campaign the wind it needs to stay in the race.

"I'm more determined than ever to see that every vote is cast and every ballot counted," Clinton said Tuesday, again claiming she has the popular vote lead. She claims that lead by counting the Michigan and Florida primaries, which were discounted because the states held early contests in violation of party rules.

Party officials are scheduled to meet later this month to consider how -- or whether -- to seat all or part of the states' delegates, and the Clinton campaign is continuing to fight for those states' delegates.

"We're back. We continue to raise money, we continue to win states. This thing goes on. I don't know why people are saying this is over," Clinton campaign chairman Terry McAuliffe told FOX News.

McAuliffe earlier told reporters that campaign finance filings will show April was Clinton's second-best fundraising month of the race. Her campaign later said she earned $22 million for the month. In April, Obama raised more than $31 million for the primary race.

With her Kentucky victory, Clinton picked up at least 33 delegates to at least 14 for Obama with an additional four yet to be awarded.

But Obama still leads overall and has steadily picked up momentum as he drives toward the 2,026 delegates needed to become the nominee of his party.

As Oregon was tallied, Obama had 1,956 total delegates, putting him within 100 of the 2,026 needed. The former first lady had 1,775.

Obama weeks ago predicted Clinton would win Kentucky. The Clinton campaign similarly indicated that Obama would likely win Oregon, where Obama invested his time and drew a crowd estimated at 75,000 over the weekend

The Beaver State has 52 delegates. It also had the distinction of staging the only contest without a designated polling day. Instead, under a vote-by-mail system, election officials tallied all ballots received by 11 p.m. on primary day.

The only primaries remaining are in Puerto Rico, on June 1, followed two days later by South Dakota and Montana.

Republicans, too, were holding primary contests in Oregon and Kentucky, but these were "beauty contests," as McCain wrapped up the nomination more than two months ago.

FOX News' Steve Brown and The Associated Press contributed to this report.