WASHINGTON/NEW YORK- US Democratic presidential candidate Bernie Sanders defeated Hillary Clinton in the West Virginia primary on Tuesday, slowing her march toward the party's nomination.
Despite the setback, Clinton is still heavily favored to become the Democratic candidate in the Nov. 8 election.
But Tuesday's loss could signal trouble for Clinton with working-class voters in the US Rust Belt, where she will need to prevail in key states such as Ohio and Pennsylvania when she takes on Trump in the general election.
Clinton in March said the country would "put a lot of coal miners and coal companies out of business" at an Ohio town hall in a comment that appeared to hurt her with voters in coal-mining states such as West Virginia.
During Clinton's visit to West Virginia and Ohio last week she repeatedly apologized to displaced coal and steel workers for her comment, which she said had been taken out of context, and discussed her plan to help retrain coal workers for clean energy jobs.
Trump, 69, won West Virginia handily on Tuesday, after his two remaining rivals, Ted Cruz and John Kasich, dropped out of the Republican race. Trump has zeroed in on Clinton's protracted battle with Sanders, a 74-year-old US senator from Vermont who pulled off a victory in Indiana's Democratic primary last week despite trailing in opinion polls.