2:10am UK, Wednesday May 21, 2008

Hillary Clinton has captured the first of two Democratic nominating tests with a big win in Kentucky.

180 barack obama in reno nevada democratic candida

Mr Obama

But rival Barack Obama was looking for an Oregon victory later that would help him reach a major milestone in the race.

Mrs Clinton had a 35-point lead over Mr Obama with 90% of the vote counted in Kentucky, a bastion of the white working-class voters who have been her biggest supporters.

"I'm going to keep making our case until we have a nominee - whoever she may be," Clinton, who has shrugged off calls to drop out before the last of the primary elections on June 3, told supporters in Louisville, Kentucky.

But the results there and in Oregon will give Mr Obama a majority of pledged delegates won in the lengthy state-by-state nominating fight with Mrs Clinton.

Mr Obama hopes that landmark signals the beginning of the end of their gruelling Democratic race to contest November's presidential election against Republican John McCain.

The Illinois senator will still be about 50 delegates short of the 2,026 needed to win the nomination at the Democratic convention in August.

But he hopes the milestone will send more undecided superdelegates - party officials who can back any candidate - flooding his way.

Mr Obama contends those superdelegates, who have been moving his way heavily in recent weeks, should support him because he won the most delegates in state voting.

She says superdelegates should reconsider their decisions because she would be a stronger opponent for McCain, an Arizona senator.

Her victories in big states like Pennsylvania and Ohio gave her a broader base of support than Mr Obama, she said.

Oregon's balloting ends at 0300 GMT. Results are expected shortly after.

A delegate count by MSNBC gives Mr Obama 1,917 delegates to Mrs Clinton's 1,725.