In the past week, one member of the U.S. House announced their 2020 retirement. Republican Paul Cook (CA-8) said he will run for the San Bernardino County Board of Supervisors. To date, four Senators (three Republicans and one Democrat) and 20 Representatives (16 Republicans and four Democrats) are not running for re-election.
As of September 23, 2019, 250 candidates are filed with the Federal Elections Commission (FEC) to run for U.S. Senate in 2020. Of those, 222—118 Democrats and 104 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.
1,448 candidates are filed with the FEC to run for U.S. House in 2020. Of those, 1,358—709 Democrats and 649 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, 2012, 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.