How will the election affect the Congress?
The makeup of Congress will be determined by the general election, with both parties needing a majority to control the House or Senate. Democrats seem to have a good chance at winning a Senate majority, while their control of the House is not in serious doubt.
Republicans now hold the Senate 53-47. Democrats must gain at least three seats to win control, or four if President Donald Trump is reelected and Vice President Mike Pence can break a tie.
In the 435-member House, Democrats are defending the majority.
Republicans hold 197 House seats and need 218 to win control.