US Democratic presidential nominee Hillary Clinton shared a stage with former rival Senator Bernie Sanders on Wednesday to appeal for youth votes in the November 8 election as opinion polls show a close race with Republican Donald Trump. Clinton told an audience at the University of New Hampshire that she would make college affordable if she wins the White House, the kind of promise that won Sanders many young supporters during the Democratic nominating contest. "We should and we will make public colleges tuition-free for families earning less than $125,000 a year," Clinton said.