White House hopefuls face next key tests

White House aspirants face their third test Saturday when Republicans square off in South Carolina, where Donald Trump enjoys a commanding lead, and Democrats battle in Nevada as Hillary Clinton hopes for a comeback. In South Carolina, Republicans will vote in a primary, while in Nevada, Democrats will caucus -- grouping themselves together by candidate to voice their support. "It's crunch time, folks," Trump, 69, told voters at a North Charleston rally, his final pitch before the South Carolina