A month ago, the GOP seemed to be the odds-on favorite to retain control of the Senate. With the tumultuous month of October behind us, the odds seem to have shifted slightly to favor the Democrats regaining control.
The Democrats have a structural advantage due to the fact that they are defending only 10 seats while Republicans are defending 24. Only one Democratic seat, the Nevada seat of the retiring Harry Reid, was considered at risk. A total of eight Republican seats, many in blue or purple states, are threatened. Many of these at-risk seats were won in the Tea Party wave election of 2010. Wave elections often allow weak candidates to win who cannot retain their seat when political conditions return to normal.
FiveThirtyEight puts the chances that the Democrats will win the Senate at over 60 percent. A recent blog post noted that four of the eight most hotly contested races have seen major shifts. Three races have shifted toward the Republicans and one toward the Democrats. Indiana, New Hampshire and Wisconsin have moved slightly toward the Republicans while Pennsylvania now favors the Democratic challenger.
Here are summaries on the battleground Senate races for Republican seats:
- In Florida, Sen. Marco Rubio’s lead over Democrat Patrick Murphy has tightened slightly, but Rubio is still the clear favorite.
- In Illinois, Sen. Mark Kirk’s seat is all but lost. Rep. Tammy Duckworth’s lead has widened to 13 points in the Real Clear Politics average after Kirk made an embarrassing comment about Duckworth’s heritage.
- In Indiana, a race previously considered a Democrat lock, Rep. Todd Young (R) was tied with former Senator Evan Bayh (D) in a recent poll. FiveThirtyEight’s models show Young’s chances of taking the seat surging from 30 percent to 45 percent. The seat is currently held by Republican Dan Coats, who is retiring.
- In Missouri, Sen. Roy Blunt is in a tossup race with Secretary of State Jason Kander. FiveThirtyEight gives the race as a 55 percent chance of going to the Democrats, a slight improvement for Blunt.
- In New Hampshire, Sen. Kelly Ayotte seems to be maintaining a margin-of-error lead over Gov. Maggie Hassan. FiveThirtyEight has downgraded Hassan’s chances of winning the seat from 67 to 56 percent. The race is still a tossup, but with slightly better odds for Ayotte.
- In North Carolina, Sen. Richard Burr’s race with state Rep. Deborah Ross is still a tossup. FiveThirtyEight puts Ross’s chances of taking the seat at 34 percent, down nine percent from two weeks ago.
- In Ohio, Sen. Rob Portman’s seat seems to be reliably Republican. Portman holds a double-digit advantage over Gov. Ted Strickland.
- In Pennsylvania, Sen. Pat Toomey has trailed Katie McGinty in nine straight polls. The race is still close, with McGinty leading by an average of less than four points, but FiveThirtyEight has moved the race from a tossup to a 73 percent chance of a Democratic victory.
- In Wisconsin, Sen. Ron Johnson’s chances are still not good. Former Democrat Sen. Russ Feingold has consistently led the race. FiveThirtyEight says that the race has moved slightly in Johnson’s favor, but Feingold still has a 90 percent chance of retaking the seat.
The sole Democratic battleground seat is Nevada. This race is a tossup between Rep. Joe Heck (R) and Attorney General Catherine Cortez Masto. Heck holds a slight advantage in the RCP average of polls, but FiveThirtyEight gives Cortez Masto almost a 60 percent chance of winning.
The current balance of power in the Senate is 54 Republicans to 46 Democrats (including independents). The Democrats need a net pickup of four seats to split control of the Senate or five seats to take a majority. In the case of a 50-50 split among the two parties, the incoming vice president can cast the deciding vote.
At this point, Democrats look likely to retain Harry Reid’s Nevada seat as well as pick up Republican seats in Illinois, Indiana, Pennsylvania and Wisconsin. These four seats would be enough to split the Senate evenly with the Republicans.
The fifth seat, to give the majority to the Democrats, will likely come from either Missouri, New Hampshire or North Carolina. All three races are tossups and FiveThirtyEight gives Democrats the edge in both Missouri and New Hampshire.
Regardless of whether Hillary Clinton or Donald Trump wins the presidency, it has been viewed as critical for Republicans to hold the Senate. The Senate has the role of confirming judges and Supreme Court justices as well as confirming treaties. Any bills from the House’s Republican majority, which is likely safe, must go through the Senate before they are signed into law by the president.
The most recent round of polling gives little hope of preserving the Republican Senate majority. As Republican Senate hopes fade, so do hopes of everything from keeping liberal justices off of the Supreme Court to repealing and replacing Obamacare.