Hillary Clinton held a slight lead over Bernie Sanders in the Kentucky primary on Tuesday, as the waning weeks of the Democratic contest have turned particularly bitter among supporters and surrogates.
The race was still close to call with about 99 per cent of the votes counted. Clinton claimed victory late Tuesday.
Sanders was due to speak to supporters in Carson, Calif., where supporters lined up hours before his event at a tennis stadium.
Clinton was seeking a victory in Kentucky to rebound from losses to Sanders in recent primaries in West Virginia and Indiana. Results are expected later in the evening in Oregon, where the state's liberal voting base was expected to favor the Vermont senator.
A loss may not disrupt Clinton's ability to capture the nomination before the convention in July, but it could prove embarrassing as her campaign tries to wrap things up.