Congress is made up of the Senate, which consists of 100 total senators (two from each state) and the House of Representatives, which consists of 435 representatives. The current Senate consists of 53 Democrats and 47 Republicans. In the upcoming election, there are 33 of the 100 Senate seats up for election. Of those 33, Democrats hold 23 of those seats and the Republicans hold 10. To maintain control of the Senate, the Democrats need to win 21 seats. To gain control, the Republicans must win 14 of the races.
In the House of Representatives the GOP is expected to keep its majority control. If Mitt Romney wins the presidency and the GOP win just four spots in the Senate, then all three branches would be under Republican control. As election season winds down, there has been a lot of attention to these important congressional races across the United States.