The Senate Races 22 October 2016

Let's start with the basics. The Republicans currently have 54 Senators, the Democrats 44 and two independent Senators are part of the Democratic caucus.

34 seats are being contested. 24 of those seats are held by Republicans and 10 held by Democrats.

For the Democrats on defense, only Nevada looks close, the race to fill the seat being vacated by Harry Reid. More on that in the explanation of the close races.

For the Republicans on defense, they look to be losing three seats: Illinois, Wisconsin and Indiana. Of the remaining 21 races, only four are close, one slightly favoring the GOP in North Carolina and three races that are flat-flooted toss-ups using the current data. Here is the graph for the current odds based on the number of Republican seats held.

Here are the trends in October. The last two weeks show momentum for the Democrats. In the very likely case of a Clinton victory, a 50-50 split in the Senate would mean a Democratic majority, as Vice President Tim Kaine would hold the deciding vote. This means that as of today, there is a 66% chance the Democrats will control the Senate. 

Probability of Republicans holding the Senate outright:
22 October: 33.9%
15 October: 41.2%
8 October: 53.8%
1 October: 43.8%

Probability of a 50-50 split: 
22 October: 32.0%
15 October: 31.0%
8 October: 29.2%
1 October: 30.7%

Probability of the Democrats taking the Senate back outright:
22 October: 34.2%
15 October: 28.8%
8 October:18.0%
1 October: 25.5%

The close races.

Nevada. Using the last 10 polls, Republican Joe Heck has an advantage, his Confidence of Victory at 62%, compared to 38% for Catherine Cortez Masto. If we look at the most recent seven polls, three favor Heck, three favor Cortez Masto and the last says the race is a tie. As older polls are replaced in the forecast, these numbers could trend Democratic.

North Carolina: As in Nevada, the Republican candidate Richard Burr has a slight lead at 66% to 34% over challenger Deborah Ross in a very heavily polled race. Unlike Nevada, recent polls do not show any trend towards the Democrat. The current median puts it at a 1% to 2% lead.

The really close races: current median poll shows a tie

New Hampshire: Seven polls are being used in the New Hampshire race. Three favor the Democrat Hassan, two favor the incumbent Ayotte and two show the race even. Looking at the most recent, the trend looks to go in Hassan's favor.

Pennsylvania: I love the Irish names in this race, Pat Toomey vs. Katie McGinty. It reminds me of The Last Hurrah, but in politics that old school, both candidates would be male. Right now, eleven polls are being used, four that favor Toomey, three that favor McGinty and four that show a tie race. That means the average would be in favor the Republican. Like North Carolina, there is no recent trend towards the Democrat. If forced to choose a winner here, right now I would bet on Toomey.

Missouri: Unlike other tight races, this one has only been polled sparsely. There are three polls this month, Once favoring the incumbent Roy Blount, one favors challenger Jason Kander and one shows a tie at 44-44. If asked to gamble here, I would politely decline, based on the scarcity of real information.

Back tomorrow with Clinton and Trump, a race with some interesting twists and turns, but one extremely likely outcome.