Romney Leads U.S. Republican Primaries, But Race Goes On

Four candidates are still running to be the Republican contender who will challenge Barack Obama for the U.S. presidency in November. Voting in ten states in the biggest round of primaries so far on March 7, known as "Super Tuesday," confirmed Mitt Romney as the leading candidate, but did not give him the number of delegates to decisively defeat Rick Santorum, Newt Gingrich, and Ron Paul. AP video