Republican Presidential Candidates Gear for Fifth Debate

Republican presidential candidates will hold their fifth and final debate for the year Tuesday night in Las Vegas. The field has changed somewhat since the last Republican debate on November 10. Real estate magnate Donald Trump remains in the lead nationally, but Texas Senator Ted Cruz has surged to the top in a key Iowa poll. Former surgeon Ben Carson, who used to be closest to Trump, is now plummeting in the polls. Zlatica Hoke reports.