Sen. Bernie Sanders prevailed over Hillary Clinton on Tuesday in the Oregon primary, according to The Associated Press, while Clinton claimed victory in a tight race in Kentucky, the day’s other contest.

Clinton raced around Kentucky in the two days before the primary, hoping to fend off Sanders in a state that she had won easily in 2008. In unofficial results late Tuesday, Clinton edged Sanders by about 1,900 votes, or less than half a percentage point, with all counties reporting. The Associated Press had not declared a winner by midnight.

The close result meant that she and Sanders would effectively split the state’s delegates. Nonetheless, winning Kentucky would give her a symbolic triumph that could blunt the effect of her loss in Oregon as she turns her attention to Donald J. Trump, her likely general election opponent.

With a lead in delegates that is almost impossible for Sanders to overcome, Clinton is moving closer each week to claiming the Democratic nomination. But her march has been encumbered by Sanders’ persistence in

the race and his success in recent contests, including victories in Indiana’s primary May 3 and West Virginia’s last week.

This weekend, bitter feelings from Sanders’ supporters spilled into view at Nevada’s state convention, which descended into chaos, prompted death threats against Nevada’s Democratic chairwoman and raised the prospect of discord at the national convention in July in Philadelphia. The fury was sparked after a dispute over convention rules and delegate qualifications that supporters of Sanders saw as unfair.

Speaking at a rally in Carson, California, on Tuesday night, Sanders said: “There are a lot of people out there, many of the pundits and politicians, they say, ‘Bernie Sanders should drop out. The people of California should not have the right to determine who the next president will be.'”

“Well, let me be as clear as I can be,” he continued. “We are in till the last ballot is cast.”

With her overwhelming support from superdelegates, the party leaders who can vote as they wish, Clinton could clinch the nomination by June 7, when six states vote or caucus, including California and New Jersey. But Sanders said he would try to persuade superdelegates to back him instead, based on his strength against Trump.