Midweek midterm elections update for July 18th
Bottom Line: We're up to our 22nd midterm election update. 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. 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: +8%
After three weeks of Democrats maintaining a six-point advantage we see that Democrats have broken back out to an eight-point advantage for the first time in a month. If it holds, it matters. Democrats have led on the generic ballot by an average of 3% to 12% thus far in 2018. Anything in the 8%+ range would likely produce a "wave" type of election. Anything in the 4% or under range would likely result in Republicans retaining complete control. At 8%, based on current data from this cycle, Democrats would be positioned to pick up 30 seats in the US House and based on the latest data in the Senate, they would likely gain one seat with at least a 50-50 chance of gaining another. Democrats would gain control of the US House and would have a realistic chance to win the US Senate despite a map that heavily favors Republicans.
It is worth noting that polling was all over the map this week with Democrats showing an advantage ranging from 4% to 13% based on the pollster – so there's a very high margin for error in the polling right now.
Until next week...