Midterm Elections: Analyzing the Battle for Congress

Midterm polling, two months before Election Day, is shedding light on the battle for Congress. While Democrats hold a stronger national environment and clear path to the House of Representatives, control of the Senate remains uncertain. Nonpartisan analysts label six key Senate races as toss-ups.

Current Polling and Prediction Markets

An Emerson College poll released on August 20 revealed Democrats with an eight-point lead on the congressional ballot. It showed 51 percent siding with Democratic candidates compared to 43 percent supporting Republicans, leaving six percent undecided.

Prediction markets reflect this division. Polymarket placed Democrats at 89 percent to win the House and Republicans at 12 percent. Its Senate market is nearly even, showing 51 percent for Democrats and 50 percent for Republicans. Kalshi favored Republicans in the Senate, pricing them at 51 percent to Democrats’ 49 percent.

These figures are market prices, not single normalized polling estimates. Prediction markets incorporate new information rapidly due to financial stakes but don’t represent a voter sample. However, they should be considered alongside polls and forecasts.

A Reuters/Ipsos poll on August 31 found President Donald Trump’s approval at 33 percent, maintaining a trend over three surveys. Democratic voters reported higher enthusiasm for November compared to Republicans, 46 percent to 31 percent, and independents favored Democrats on the congressional ballot.

Democrats’ Advantage in the House

Democrats have a national advantage supported by competitive House seat distribution. As of August 25, Cook Political Report identified 21 districts as toss-ups, with 16 Republican-held and five Democratic-held. Seven more seats leaned Republican, while nine leaned Democratic.

These ratings consider district politics, candidate strengths, and the national environment. A higher number of Republican seats are contentious.

Decisive House Districts

Important House races are concentrated in suburban, exurban, and mixed urban-rural districts, many held by Republicans. Examples include Michigan’s 7th and 10th districts, New York’s 17th, Pennsylvania’s 8th, and Virginia’s 2nd. All show competitive dynamics.

Public district polling is less comprehensive than national polling, adding uncertainty to precise comparisons. Ratings highlight potential battlefields but don’t establish measurable leads.

Senate Races and Challenges

The Senate poses opportunities for Democrats, requiring a net gain of four seats for control. Cook rated six races—Alaska, Iowa, Maine, Ohio, Texas, and Michigan—as toss-ups as of August 20.

Polling shows competitive dynamics in these states. Suffolk University’s poll in Iowa indicated a close Senate race, and EPIC-MRA in Michigan reflected similar scenarios. Polling margins of error need careful consideration.

Impact of Trump’s Approval Ratings

Trump’s approval ratings pose challenges for Republican candidates. Surveys from Emerson and Reuters/Ipsos highlight concerns over the economy and living costs.

Candidate effects and local issues are crucial in competitive Senate races, like those seen in Iowa and Alaska.

Overall Concerns for Both Parties

Republicans defend numerous toss-up seats, while Democrats seek victories in diverse states. Polling leads may shift due to turnout and undecided voters. Democrats seem better positioned for the House, with the Senate remaining a contested territory.

Editors: Alfred Joyner, Emma Lee-Sang, Tony Phillips.