South Carolina voters go to polls

South Carolina voters go to the polls later in a key vote in the US Presidential campaign.

Today's Republican primary will be an important battle for Newt Gingrich, who has been enjoying a surge in popularity.

If the former House speaker defeats frontrunner Mitt Romney in South Carolina, it may renew doubts about whether more moderate former Massachusetts governor Romney can rally the party's conservative core, where he is viewed with suspicion.

No Republican since 1980 has won the party's nomination without first winning in South Carolina.