Senate Update: The Last Week Has Been Very Kind To Democrats’ Hopes For
Thanks to big shifts in several key races, Democrats now have a 73 percent chance of winning the Senate, according to the FiveThirtyEight polls-plus forecast, and a 72 percent chance according to polls-only. Both those numbers are up by more than 15 percentage points from last week, when the polls-plus model gave them a 56 percent chance and the polls-only model 54 percent.
In our last Senate Update, I noted a growing divergence between our Senate and presidential forecasts. The presidential race had moved quickly towards Democrat Hillary Clinton; the battle for control of the Senate had ticked a bit towards the GOP. But the forecasts have snapped back into closer alignment as Democratic Senate chances have improved.
What’s so interesting about the upswing in Democrats’ fortunes is that many Senate races haven’t shifted much. In the average Senate race, the margin separating the two major-party candidates has shifted toward the Democrat by just over 1 percentage point over the last week, according to our polls-only model. But that includes noncompetitive races. Control of the Senate is coming down to six key states, with Democrats needing to gain four seats to win a majority if Clinton wins the White House. And in the crucial contests, there has been more movement.