Four Senators (three Republicans and one Democrat) and 28 Representatives (20 Republicans and eight Democrats) are not running for re-election in 2020. In 2018, 55 total members of Congress—18 Democrats and 37 Republicans—did not seek re-election. In the past week, no members of Congress announced 2020 retirements.
As of November 18, 2019, 290 candidates are filed with the Federal Elections Commission (FEC) to run for U.S. Senate in 2020. Of those, 253—134 Democrats and 119 Republicans—are from one of the two major political parties. In 2018, 527 candidates filed with the FEC to run for U.S. Senate, including 137 Democrats and 240 Republicans.
1,787 candidates are filed with the FEC to run for U.S. House in 2020. Of those, 1,679—840 Democrats and 839 Republicans—are from one of the two major political parties. In 2018, 3,244 candidates filed with the FEC, including 1,566 Democrats and 1,155 Republicans.
On November 3, 2020, 35 Senate seats and all 435 House seats are up for election. Of those Senate seats, 33 are regularly-scheduled elections, while the other two are special elections in Arizona and Georgia. Twelve are Democratic-held seats and 23 are Republican-held seats. In the House, where all the seats are up for election, Democrats currently hold a 233-seat majority.