Georgia's Senate race heads to a runoff that could determine control of chamber

The balance of power in Congress is still undetermined, two days after Election Day, as results in several Senate races in Georgia, Arizona, and Nevada are still being tallied. Those races will be key to which party controls the Senate for the next two years. CBS News senior congressional correspondent Mark Strassman has more on what Georgia's Senate runoff means for both parties' efforts to control the chamber.