Republicans worst nightmare is becoming a reality as Donald Trump’s unpopularity is threatening to take the Republican Senate majority down with him. An influx of new data from several polls now gives Democrats a 61 percent chance of winning control of the chamber in November.
Included within this 61 percent is a 17 percent chance that the chamber will split 50-50. In the event of a tie in the Senate, the vice president casts the tie-breaking vote.
Democratic nominee Hillary Clinton is overwhelmingly favored to win the presidency, which would make her running mate Tim Kaine the tie-breaking vote as vice president.
This is a big shift with only days before election day. As of Friday, it was showing that Republicans had a nearly 60 percent chance of keeping the majority. The flip was caused by new data in the Indiana race, moving it from a 50 percent chance for each candidate to a 99 percent likelihood of flipping toward the Democratic side.
Democrats need to win five seats among the 11 most competitive races. Ten of these seats are held by Republicans, and one by a Democrat, Harry Reid of Nevada, who is retiring.
That the Democrats are favored in this election should not be surprising. In recent history, Democrats have done better in presidential election years than in midterm years, when turnout is lower. Most of the senators up for re-election last went before the voters in the Republican wave election of 2010 — when the G.O.P. made big and broad gains in an anti-Obama environment — leaving Republicans with several potentially vulnerable incumbents.
This year, the Democrats are defending only 10 seats while the Republicans have to preserve 24. On fundamentals alone, Democrats would have about a 50-50 shot to win the Senate. The latest Senate polling improves this figure to 61 percent.
But that doesn’t mean Democrats have the majority sewn up. If Republicans’ numbers improve even a little, they could reach 51 seats and control the chamber regardless of who is vice president.
With so many seats remaining uncertain, the race could still tip in either direction, with Republicans possibly retaining a slim majority or Democrats running the table. As of today, the most likely outcome is a tie.
