Senate Picture, August 9th, with Rasmussen
Most likely outcome: Democrats 52 seats, Republicans 47 seats, Charlie Crist 1 seat
Of the 100 Senate seats, 86 are either not up for re-election, or have a polling average where one party has a 100% chance of victory (if the election were held today). Among those 86 seats, there are 48 Democrats, and 38 Republicans. Here is a chart featuring the other 14 campaigns:
Senate picture, competitive campaigns chart, August 9th, with Rasmussen
The 48 currently safe Democrats, plus the 4.20 wins projected in these 14 campaigns, comes out to 52.20 Democrats, or 52 seats. Charlie Crist is also projected to win one seat.
Senate Picture, August 9th, without Rasmussen
Most likely outcome: Democrats 54 seats, Republicans 45 seats, Charlie Crist 1 seat
Senate picture, competitive campaigns chart, August 9th, without Rasmussen
The 48 currently safe Democrats, plus the 6.00 wins projected in these 14 campaigns, comes out to 54.00 Democrats. Charlie Crist is also projected to win one seat.
Very little overall change in the numbers from last week, but that really isn't surprising for August. Outside of the states which still have primaries, the major ad buys will not begin until after Labor Day. Still, it won't be long before I am posting an update to the forecast every evening.
- Methodology here
- All polls taken from Pollster.com
- * = Has primary challenger, but heavy favorite
- The "current Dem winning %" column projects the chance of Democratic victory if the election were held today. It is not meant to predict the chance of the Democratic candidate winning in November.
- Every Senate seat not listed here currently has either a 0% or a 100% chance of a Democratic victory.
- Knedrick Meek is projected as the winner of the Florida primary because he leads in 3 of 4 polls, even though Jeff Greene narrowly leads the average.
Also, I ran the 25-day simple mean methodology against another forecasting giant, Real Clear Politics. Across the 48 Presidential, Senatorial, and Gubernatorial general election campaigns with the closest final polling averages since 2008 where Real Clear Politics made a final projection, the 25-day simple mean was much more accurate:
Real Clear Politics
Mean Error: 2.91
Median Error: 2.14
25-day simple mean
Mean error: 2.39
Median error: 1.65
That's a big gap in accuracy between the two methodologies.
The error being measured is final projected margin to final actual margin. Dave Leip's Atlas of Elections is used as the source for the final margin. You can see all of the work backing up these claims here.