Democrats Gain Lead in November Congressional Election Polls

Recent polling and prediction market data indicate a shift in momentum toward the Democratic Party ahead of the November congressional elections. A Marquette University Law School poll released September 16 shows Democrats leading Republicans 54% to 41% among likely voters, an increase from the 51% to 45% margin seen in July. This trend is mirrored in a New York Times/Siena University poll, which finds likely voters favoring Democratic candidates in congressional districts by nearly 9 percentage points.

Donald Trump has seen his overall approval rating decline to 37%, with 63% of voters disapproving of his performance. While he maintains stronger support for border security and immigration, his ratings have fallen below 30% regarding the economy, inflation, and the war with Iran. These declines coincide with rising energy costs, as oil has exceeded $100 per barrel and gasoline has surpassed $4 per gallon.

Prediction markets also reflect this shift. Kalshi assigns Democrats a 54% chance of winning the U.S. Senate, while Polymarket places the odds at 59%. These markets have remained volatile since the U.S.-Iran war began on February 28, 2026. Voters currently cite inflation and the cost of living as their primary concerns, followed by the general economy and the ongoing conflict involving Iran, Israel, and the United States.