Hover over a state for details. Use the radio buttons below to select a scenario:
No Blue Wave
Tossups break 50/50
Democrat Change In Seats
Republican Change In Seats
Who Controls Chamber
As you can see in the table above, the polling indicates that even under the best-case scenario for the GOP, they will lose about nine seats. However, this would be insufficient to flip the chamber to Democrat control. If the "blue wave" were to materialize in full, the Dems could be sitting on a 49 seat gain in the chamber -- basically a reversal of the current balance of power to 244 Democrat seats.
We can make an assumption that 2018's "tossup" seats are true dead heats. There is precedent for this, in that the GOP won 56% and 48% of tossup seats in the 2014 and 2010 midterms respectively. That's not a surprising result if the seats are actual tossup (coin-toss) races. If the Democrats pick up about half of this year's 39 tossup races, that gives them twenty seats. Add that to the ten non-tossup seats they are already forecast to win, and you have a 30 seat gain. That's enough to flip the chamber.