Control of the U.S. Senate has become a pure toss-up less than two months before the midterm elections, according to Decision Desk HQ, whose model moved from a two-point Republican edge at the end of August to a 50-50 average outcome across one million simulations. Republicans currently hold 53 seats to Democrats’ 45, with two independents caucusing with Democrats, and Democrats need a net gain of four seats for a majority. The Cook Political Report rates six Senate contests as toss-ups. Democrats are defending competitive opportunities in Michigan and Maine while expanding their targets to Texas, Iowa, Alaska, Ohio and North Carolina. Senate advertising is projected at $3.4 billion, up from $2.8 billion in fall 2025. President Donald Trump’s economic approval rating fell to 32% in July from 40% in March 2025, adding pressure to Republican candidates. Decision Desk HQ gives Democrats a 67% chance of retaking the House.