The Senate Snapshot continues to crystallize. It still shows 52 Democratic seats, and only a 1% chance of a Republican takeover.
Senate Competitive Campaigns Chart
Margins are based on the simple average of all published polls in which the majority of interviews were conducted on or after October 8th. No polls will be removed form the averages between now and Election Day. Only campaigns closer than 12.0% are listed. All polls used in the averages are taken from Pollster.com. Click here for the Senate Snapshot methodology.
Seat Odds Outcome Chart
Even though Democrats only lead in 51 seats, given narrow Republican leads in Illinois, Nevada, Colorado and Pennsylvania, 52 Democratic seats is the most likely outcome. In fact, 53 is slightly more likely than 51, according to the Snapshot.
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Allow me go into a bit more detail on the “cuirrent Dem win %” column percentages in the Senate Competitive Campaigns Chart:
- First, they are based on if the election were held today, and all the polling averages presented above were final. Things can change, but I don’t want to get into the business of predicting how they will change. It would either require too many assumptions or years of research (quite literally).
- Second, the percentages assume that there is an equal chance of the polls erring in favor of Democrats or Republicans. This is because the 145 Presidential, Senatorial, and Gubernatorial campaigns I looked at found that there was an even chance of error in favor of both parties. That may not be the case anymore, because of new polling problems like cell-phone bias. However I am not going to assume there is a hidden Democratic vote--which I very much hope there is, despite personal doubts--until it starts showing up in the data (which we won’t have until after the election).
- This is an empirical system, based neither on my gut nor any higher math. The percentages represent the frequency with which the final 25-day polling average has been observed to be incorrect by a large enough amount to swing an election based on the current margin of that election. Half of the frequency, actually, since polling error did not appear to benefit either party in the campaigns I looked at.
- These are percentages, not absolutes. If a campaign is still between 1% and 99%, then both candidates would have a chance of winning even if the election were to end today.
Hope that helps explain what these numbers mean. The goal is to provide the most accurate and understandable context to polling on Senate campaigns. This is not only because I am a polling junkie, but because I strongly believe we can only do the best activism if we have the most accurate information.
