Factors that could affect the balance of power in Congress

Republicans hold a slim majority in the House, while the Democrats' margin in the Senate is slimmer. Seats are being vacated, districts redrawn, and the pull of presidential candidates are all likely to play a major role in the balance of power in Congress. CBS News congressional correspondent Scott MacFarlane details the key races that could swing control of either chamber.

Factors that could affect the balance of power in Congress
Republicans hold a slim majority in the House, while the Democrats' margin in the Senate is slimmer. Seats are being vacated, districts redrawn, and the pull of presidential candidates are all likely to play a major role in the balance of power in Congress. CBS News congressional correspondent Scott MacFarlane details the key races that could swing control of either chamber.