By Jim Ellis
March 12, 2018 — One of the keys to deciding the 2018 Senate election cycle is seeing how the 10 Democrat senators forced to defend states that President Trump carried will fare. A series of new Axios/Survey Monkey polls in these aforementioned places produces good news for Republicans, but the data appears flawed.
According to the methodology, 17,289 registered voters participated in the surveys within the 10 states between Feb. 12 and March 5. Obviously, the sampling period is too long, unless the polls were conducted successively, but there is no indication of such. The voluntary online response system also brings the polling reliability factor into question.
That being said, even suspect studies are valuable to analyze because more opportunities are provided to detect flows and trends within the various sampling sectors.
The results of the 10 polls are as follows (listed in alphabetical order):
- Florida: Sen. Bill Nelson (D) 53% | Gov. Rick Scott (R) 43%
- Indiana: Sen. Joe Donnelly (D) 45% | Generic R 51%
- Michigan: Sen. Debbie Stabenow (D) 49% | Generic R 45%
- Missouri: Sen. Claire McCaskill (D) 44% | AG Josh Hawley (R) 55%
- Montana: Sen. Jon Tester (D) 42% | Generic R 55%
- North Dakota: Sen. Heidi Heitkamp (D) 47% | Generic R 49%
- Ohio: Sen. Sherrod Brown (D) 50% | Rep. Jim Renacci (R) 45%
- Pennsylvania: Sen. Bob Casey Jr. (D) 52% | Rep. Lou Barletta (R) 43%
- West Virginia: Sen. Joe Manchin (D) 43% | Generic R 52%
- Wisconsin: Sen. Tammy Baldwin (D) 49% | Generic R 46%
As we can see, when contrasting these results with other published polls conducted in the budding races, most of the above data is too optimistic from a Republican perspective. This is particularly so when the incumbent Democratic senator is paired only with a generic Republican.
Interestingly, one race that has polled consistently within the margin of polling error, Florida, is the Democrats’ best showing within this Axios/Survey Monkey series. There is no other Sunshine State published poll that forecasts Sen. Nelson is such a strong position.
While it is reasonable to believe that the quoted margins in Indiana, Missouri, and West Virginia could end relatively close to the spreads depicted in these studies, there is no available data today that illustrates such margins. Confirming numbers for the North Dakota result do exist, however.
The Ohio (D+5) and Pennsylvania (D+9) polls appear reasonable because other surveys arriving at similar conclusions can be found.
The pure outliers look to be Montana (generic R+13), Michigan (D+4), and Wisconsin (D+3). There is no available data to suggest that Sen. Tester is even trailing any of his Montana Republican opponents, let alone falling behind by a double-digit deficit. Considering the status of GOP Senate candidates in Michigan and Wisconsin, seeing incumbents Stabenow and Baldwin leading by only small numbers against placebo Republicans also seems probable.