Each cycle I provide analysis aimed to provide insight that cuts through the noise. Throughout the cycle, I brought you the midweek midterm election update. As of this entry, Republicans have picked up three Senate seats and Democrats have gained 26 seats in the US House. Democrats are also leading the national popular vote by 7.1%.
Below is my final analysis from yesterday along with my methodology and logic. First, here's what history tells us about midterm elections.
Since the advent of the current two-party system (39 midterm elections), we've averaged the President's party losing 4 Senate seats and 30 seats in the House. If that happens this year Democrats would retake control of both chambers of Congress. Democrats only need to flip two Senate seats to retake control and they need 24 seats in the House (only 23 additional seats based on the current composition). History is on the side of the Democrats reclaiming control going into this cycle.
There are only three times that the incumbent President's party has gained seats (1934 during FDR's first term, 1998 during Bill Clinton's second term and 2002 during George W. Bush's first term) thus only 3 out of 39 midterm elections have resulted in the President's party gaining seats. Here's another way of looking at it... History suggests there's a 92% chance Democrats will gain Congressional seats this year. The question becomes how many. That's where it's helpful to look at the history of generic ballot polls and outcomes. These are the past four cycles:
The first number is the average generic ballot polling on Election Day and the second is the actual result:
- 2014: GOP +2.4 - GOP +5.7 = GOP +3.3%
- 2010: GOP +9.4 - GOP +6.8 = GOP -2.6%
- 2006: DEM +11.5 - DEM +7.9 = DEM -3.6%
- 2002: GOP +1.7 - GOP +4.6 = GOP +2.9%
Polls average being off by about 3% - however history has shown that the party with a generic ballot advantage has always performed the best in the midterm elections. This is analogous to a "home field advantage" and represents about a third of the picture when attempting to determine the likely outcome of elections. As of today, the generic ballot says (average of accredited polling over the past week) ...
Current: DEM: +6.85%
That’s the narrowest margin in six weeks for Democrats and it also narrows up the window for the most competitive races a bit more as well. Democrats have led on the generic ballot by an average of 3% to 12% in 2018. We’re wrapping up the cycle right in the middle of the range this year. Individual candidates and issues in specific races can heavily influence outcomes however the general mood slightly favors Democrats nationally as of today which could be an indication of how independent voters may break in the booth.
In the House, my range last week was 27 to 32 based on a generic ballot of 7.9% for Democrats. Based on the latest data my expected range is 23 to 28 pickups for Democrats. To be clearer the high side of this cycle for Republicans is hanging onto control of the House by about one seat with all other outcomes favoring Democrats taking control by up to five seats. In other words, it’s tight. Super tight. The Senate isn’t. Republicans will hold serve. My range for the Senate is 1 to 4 pickups for the GOP with two net pickups being the most likely outcome.
As mentioned at the onset, an average outcome would be a loss of four seats in the Senate and 30 seats in the House. Republicans are positioned to fare better than those averages. This is set to be a better than average midterm election cycle for Republicans – even if it might not feel that way based on specific outcomes.
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