Santorum emerges as main Republican rival

Rick Santorum is poised to establish himself as the top conservative alternative to Mitt Romney, a day after jolting the Republican US presidential race by coming within eight votes of winning the Iowa caucuses.

Mr Romney barely defeated Mr Santorum in Iowa, where the party held its first contest in the race to find a challenger to President Barack Obama. Until recently, Mr Santorum had been polling in the low single-digits and was seen as having little hope of being a top contender.