PORTLAND, Ore. -- Oregon voters made their choices clear in Tuesday's primary election, casting their ballots in bulk for Senator Barack Obama for the Democratic presidential nominee.

Used to an irrelevant May primary, Oregonians flocked to drop boxes on election day to vote in the tightly contested Democratic presidential contest.

More: Obama wins most exciting Ore. primary in 40 years

Obama stepped to the brink of victory in the Democratic presidential race Tuesday night with his Oregon win and moved within 100 delegates of the total needed to claim the prize at the party convention this summer.

Hillary Rodham Clinton won the Kentucky primary.

Details: Clinton wins Kentucky

Obama had already looked like a sure winner in Oregon after his record-setting rally on Portland's waterfront Sunday. The real question was whether victory in Oregon would earn him the Democratic nomination.

Voters sounded happy to have their chance to weigh in on such a historic election, since few people had expected the presidential race to still be competitive by the time it got to Oregon.

More: Could Oregon decide the Democratic nominee?

Check: Election results

All three Presidential candidates have made visits to the state in the past week.

Obama, Clinton and John McCain have all come, and Hillary's husband Bill and daughter Chelsea have also compaigned in the state.

Sen. Clinton appeared on a Town Hall Meeting in KGW Studios Friday that was televised across the state. Then Sen. Obama held an open-air rally on Portland's waterfront Sunday that attracted about 75,000 people, the largest political campaign rally in the United States this year.

While the Presidential candidates have attracted most of the attention, there are plenty of local races that have also been hotly contested.

The state's largest city selected a new mayor -- commissioner Sam Adams -- after incumbent Portland Mayor Tom Potter decided not to run for re-election. The race pitted long-time city political insider Adams against local businessman Sho Dozono.

More: Adams wins mayoral race

Several Democrats battled down to the final day for the chance to run against incumbent Senator Gordon Smith.

"I was exhausted a few days ago, but then I got a full night's sleep," said Oregon House Speaker Jeff Merkley, who defeated Portland lawyer Steve Novick for the Democratic Senate nomination.

More: Merkley wins Senate seat

There won't be much rest for Merkley. With just five months to go until the general election against incumbent Sen. Gordon Smith, outreach to disaffected Republicans and Oregon's large pool of nonaffiliated voters will have to start immediately, Merkley noted.

One of the nastiest races has been between former state representative Kevin Mannix and Mike Erickson for the vacant U.S. House seat in District 5.

KGW and The Oregonian projected Erickson as the winner in Tuesday's primary.

More: Erickson projected winner in ugly race

Mannix did not concede until Wednesday morning and said he would not support Erickson.

The race had turned negative when an e-mail from the Mannix side suggested Erickson, a pro-life candidate, had paid for an abortion for a woman he impregnated. Erickson eventually admitted to the relationship, driving the woman and giving her money, but still denied paying for her abortion.

Mannix told KGW Tuesday night that he would not support Erickson, even though they are members of the same party, because he believes he is a dishonest candidate.

Associated Press writer William McCall in Portland contributed to this report.

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