Part of the Which party will control Congress after the 2026 midterm elections? topic →
Split control means one party holds the House while the other holds the Senate. This is the modal outcome because the chambers are trending differently: Democrats are favored in the House (82%) while Republicans hold a narrow Senate edge (53.5%). The probability splits into two paths: a Democratic House with Republican Senate (82% × 53.5% ≈ 44%) plus a Republican House with Democratic Senate (18% × 47% ≈ 8%), totaling approximately 52%. The Maine Senate race (Platner leading Collins by 7-9 points) and North Carolina trending Democratic provide some Democratic upside for the Senate, but Republicans retain a structural advantage in the upper chamber given the 2026 map.
Silver Bulletin reports Democrats' lead is now stronger than at the same point in 2018 (D+6.5), with Republicans' support declining from 42.3% to 41.6% through May 2026
Prediction markets now show Republicans with a slight edge in the Senate, reflecting the challenging map for Democrats who need to flip 4 seats
NYT/Siena poll shows D+11 environment; Data for Progress finds D+8; comparable to 2018 wave
Fox News poll shows 39% approve/61% disapprove; only 24% approve of handling of inflation
Pan Atlantic Research poll shows Platner (D) at 48%, Collins (R) at 41% among likely voters
