In the past week, one Republican member of the U.S. House announced his retirement. On September 30, Rep. Mac Thornberry (TX-13) announced that he would not seek re-election in 2020. To date, four Senators (three Republicans and one Democrat) and 22 Representatives (17 Republicans and five Democrats) are not running for re-election. In 2018, 55 total members of Congress—18 Democrats and 37 Republicans—did not seek re-election.
Thornberry was first elected to Congress in 1994 and last won re-election in 2018 by a margin if 64.6 percent.
As of September 30, 2019, 254 candidates are filed with the Federal Elections Commission (FEC) to run for U.S. Senate in 2020. Of those, 226—121 Democrats and 105 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.
1,478 candidates are filed with the FEC to run for U.S. House in 2020. Of those, 1,385—717 Democrats and 668 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, one is a special election in Arizona, and another is an expected special election in 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 235-seat majority.