Divides Deepen Among Rivals in GOP at 4th Debate

Deep differences among the candidates over everything from immigration to the use of military force were exposed at Tuesdayís Republican primary debate, where front-runners Donald Trump and Ben Carson often had to cede the spotlight to a full stage of spirited competitors.

Even Jeb Bush, who has struggled for airtime during past face-offs, was able to elbow his way into the fray, taking shots at President Obamaís economic record and Trumpís immigration plan.