News and Commentary

On Election Morning, What Are The Odds Republicans Keep House, Senate?

This article has been updated to include the latest data.

We’ve finally arrived at the day of “the most important midterm elections in recent history.” When the dust settles, who will have control of the House and the Senate? According to the most recent polling analysis by Nate Silver, on the morning of the election, the odds are virtually mirror images of each other, with the GOP about as likely to keep the Senate as the Democrats are to take the House.

Since the Kavanaugh confirmation circus, Republicans’ chances of keeping the Senate have strengthened. For the last few weeks, Real Clear Politics‘ average of the key polls has given Republicans 50 relatively “safe” Senate seats and narrow leads in two of the seven “tossup” races (Missouri and Nevada). On election morning, however, RCP only gives Republicans 49 relatively safe seats, having shifted Tennessee into the “tossups” column (the Republican leads by 5 points). Last week, RCP gave Democrats 44 relatively secure seats; that number has dwindled by one (West Virginia) to just 43.

According to Silver’s FiveThirtyEight, Republicans now have a 4 in 5 chance (81%; down by over 4% in just the last few days) of maintaining control of the Senate, giving the Democrats just a 1 in 5 chance (19%) of taking over. Silver projects Republicans to end up with 52 seats and Democrats with 48, a net gain of one seat for Republicans and one seat more than is needed for the 51-seat majority. Silver currently gives Republicans an 80% chance of gaining up to four seats or losing up to two, and just a 10% chance that they gain more than four or lose more than two.

As their Senate hopes dwindled over the last few weeks, Democrats increasingly looked to the House as their best chance at wresting at least one chamber of Congress out of the hands of the GOP. And, unlike with the Senate, the Democrats’ odds of doing so are quite good; in fact, they’re slightly better than the Republicans’ chances of keeping the Senate.

Real Clear Politics‘ poll averages on the morning of the election show Democrats with 203 seats that are “safely” blue, including 15 that are “likely” to go their way and 15 that “lean” Democrat. Republicans have 194 “safe” seats (20 likely and 25 leaning). Last week, RCP gave Republicans 196 “safe” seats and Democrats 203. If RCP’s “safe” predictions hold up, Democrats only need 15 of the 38 tossup seats to attain the 218-majority in the House. Republicans, meanwhile, need to win 24. Thirty-three of the 38 tossups are currently held by Republicans.

In numbers that resemble those for the Senate, but favoring the other party, FiveThirtyEight sets the odds dramatically in the Democrats’ favor. According to Silver’s analysis, the Democrats have a 7 in 8 chance (88.1%) of winning control of the House, while Republicans have only a 1 in 8 chance (11.9%). That’s an over 14-point improvement for Democrats since early October.

Silver projects the most likely outcome to be Democrats ending up with 234 seats and Republicans with 201. He gives Democrats a 10% chance of gaining more than 59 seats, as well as a 10% chance of gaining fewer than 21 seats. According to his models, Democrats thus have an 80% chance of winning 21 to 59 seats, and are most likely to win around 39 seats.

Related: Here Are The Most Costly Races In The House & Senate

This article has been updated to include the latest data.