One hundred days before the US midterm elections on 3 November, Donald Trump’s Republican Party confronts a deeply adverse political landscape, with forecasters projecting a high likelihood that Democrats will capture the House of Representatives while Republicans narrowly retain control of the Senate. According to Decision Desk HQ, Democrats stand a 59 per cent chance of winning a 224–211 majority in the House, erasing the GOP’s historically thin advantage. The president’s party customarily loses seats in midterm contests, but the scale of projected losses is fuelled by a convergence of voter discontent over living costs and the protracted war with Iran, which has pushed petrol prices above $4 a gallon and kept inflation elevated.

House Democratic leader Hakeem Jeffries has announced a campaign centred on an “affordability” agenda, promising to target grocery, fuel, housing and health care costs. Democratic strategists point to polls suggesting voters now trust the party more than Republicans on managing inflation, health care and even immigration – a longtime Republican strength. From the Republican side, Speaker Mike Johnson frames the choice as one of “common sense” against an increasingly leftist Democratic Party, vowing to highlight border enforcement, tax cuts and the SAVE America Act, which Trump insists is needed to prevent voter fraud. Democrats counter that the legislation is designed to suppress legitimate ballots. Republicans have also profited from gerrymandering, with a redrawn electoral map yielding a net gain of between five and twelve safe seats, sharply reducing the number of genuinely competitive House races to less than one in twenty, according to George Washington University political scientist Sarah Binder. Party campaign committees and allied groups hold a tens-of-millions-of-dollars financial edge over Democratic counterparts.

The Iran war, deeply unpopular in American opinion surveys, is exacting an electoral toll. Iranian state media, citing US polls, report that only 37 per cent of Trump’s own supporters now back the conflict if it causes higher prices, down from 50 per cent in May. The disruption of Red Sea shipping by Yemen’s Ansar Allah movement has contributed to energy market turmoil and the nationwide petrol spike. Four American soldiers killed in recent fighting have amplified Democratic criticism of the administration’s competence; Representative Sara Jacobs accused officials of “incompetence” leading to the loss of at least 18 service members. Even some Republicans privately acknowledge that an end to the war would be the best electoral scenario, though White House aides insist Trump can manage both the conflict and the economy. A senior official close to the administration warned that any scenario placing US ground forces inside Iran could further depress turnout among the MAGA base.

If Democrats win the House, they would seize control of subpoena authority and investigative committees, exposing the administration to two years of inquiries and potentially a third impeachment effort. A divided government – with a Democratic House and Republican Senate – would stall Trump’s legislative agenda while granting Democrats a national platform from which to scrutinise the war, administration ethics and efforts to reshape voting rules. The Senate contest, by contrast, favours Republicans: holding a 53–47 majority, they are projected by Decision Desk HQ to cling to control via a 50-50 split, with Vice President JD Vance casting tie-breaking votes. The elections will be held on 3 November 2026.