Election ad spending in the U.S. 2019-2020, by race
It was calculated that between January 2019 and August 2020 the Democrats spent 444.2 million U.S. dollars on advertising for the U.S. senate. In the same period the Republicans spent slightly more on senate elections, namely 463 million U.S. dollars. In total, U.S. Senate elections cost advertisers 912 million dollars at that time.