2018 Midterm Forecast

Updated 10/13/18 3:00 PM

Democrats are likely to win the House and the Republicans are likely to hold the Senate.

US Senate

Chance of Democrat Control 30%
Chance of Republican Control
Expected Democrat Seats 48
Between 37 - 56
Expected Republican Seats
Between 44 - 62

View Senate Races by State:

Candidate Expected Vote Share Chance of winning

US House

Chance of Democrat Control 77%
Chance of Republican Control
Expected Democrat Seats 223
Between 202 - 250
Expected Republican Seats
Between 185 - 233

Chances Over Time




This model works by constructing a likely vote from current national, state, and district polling data as well as past elections. Then 10,000 simulated elections are run for each state/congressional district to determine a range of possible outcomes.

In states where the primaries have not yet been held for the Senate, the candidates most likely to win are used as placeholders.

Because Vice President Pence breaks any tied vote in the Senate, the odds of a tie are factored into chance of GOP control.

The Missisipi Special Election will take place as a non-partisan Jungle Primary on Election Day. The probabilities displayed simulate the chances of participating and winning the final runoff election for each candidate.

In California, the two candidates listed are both Democrats who will be facing off against each other due to the nature of the Jungle Primary in which all candidates from all parties face off.

As the two independent Senators Angus King and Bernie Sanders have caucused with the Democrats throughout their time in the Senate, they are included in the seat estimates and control probabilities for the Democrats. Gary Johnson, the Libertarian, has not stated a preference at this point and a scenario where he controls the balance of power will be considered "No-Overall Control".

For independent and third party candidates running in House elections, a best guess at third party vote share based on historic results is provided.