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Chance the Democrat wins (41.5%)
Chance the Republican wins (58.5%)
We'll be updating our forecasts every time new data is available, every day through Nov. 6.
The Classic version of our model projects a race’s outcome by taking a weighted average of polls of a district (if available), polls of similar districts (CANTOR) and non-polling factors (fundamentals). It is then reverted toward a mean based on long-term trends in midterms and presidential approval ratings.
R+6.6
Adjusted polls
R+7.3
CANTOR
D+0.7
Fundamentals
R+11.7
Experts
R+7.1
Lite
R+1.4
Classic
R+4.8
Deluxe
<0.1
<0.1
Historical adjustment
Key
More weight
Less
We've collected one poll for the Michigan 7th. We’re adjusting poll results in three ways: Polls of registered voters or all adults are adjusted to a likely-voter basis; older polls are adjusted based on shifts in the generic congressional ballot since the poll was conducted; and polls are adjusted for house effects (the tendency for a firm’s polls to lean toward Democrats or Republicans). Polls with larger sample sizes and those conducted by higher-quality polling agencies are given more weight, as are more recent polls.
Adjustments | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
dates | pollster | sample | weight | Driskell | Walberg | margin | likely voter | Time-line | House effects | Adjusted margin | |
Feb. 19-21 2/19-21 | DCCC Targeting Team D | 400 | RV | 0.36 | 37% | 41% | R+4.0 | 0.2 | 0.6 | 2.9 | R+6.6 |
Key
A = adults
RV = Registered voters
V = voters
LV = likely voters
= partisan poll
Our district similarity scores are based on demographic, geographic and political characteristics; if two districts have a score of 100, it means they are perfectly identical. These scores inform a system we use — CANTOR, or Congressional Algorithm using Neighboring Typologies to Optimize Regression — to infer what polling would say in unpolled or lightly polled districts, given what it says in similar districts.
Sim. score | Polling avg. | ||
---|---|---|---|
WI-6 | 78 | R+15.2 | |
MI-6 | 77 | R+2.7 | |
PA-16 | 75 | R+3.1 | |
IL-16 | 75 | R+14.6 | |
WI-8 | 73 | — | |
OH-15 | 73 | — | |
IN-9 | 72 | R+7.6 | |
OH-5 | 72 | — | |
MI-4 | 71 | — | |
MI-2 | 70 | R+8.0 |
The Classic and Deluxe versions of our model use several non-polling factors to forecast the vote share margin in each district.
Factor | Impact | Explanation |
---|---|---|
Incumbency | 3.2 | Tim Walberg has been elected to 5 terms. Congress has only a 20.1% approval rating, reducing the incumbency advantage. |
District partisanship | 5.1 | MI-7 is 14.0 percentage points more Republican-leaning than the country overall, based on how it has voted in recent presidential and state legislative elections. It voted for Trump in 2016 and Romney in 2012. |
Incumbent's margin in last election | 5.8 | Walberg won by 15.0 percentage points in 2016. |
Generic ballot | 7.0 | Democrats lead by an average of 8.6 percentage points in polls of the generic congressional ballot. |
Fundraising | 4.0 | As of Oct. 17, Gretchen Driskell had raised $1,813,000 in individual contributions (66% of all such contributions to the major-party candidates); Walberg had raised $943,000 (34%). |
Incumbent's voting record in Congress | 1.7 | Walberg has voted with Republicans 85% of the time in roll-call votes in recent sessions of Congress. |
Challenger experience | 2.0 | Driskell has held elected office before. (So has Walberg, but this is accounted for in our incumbency calculation.) |
Scandals | 0.0 | Neither candidate is involved in a scandal. |
Total | D+0.7 |
The Deluxe version of our model calculates an implied margin for each race based on expert race ratings from The Cook Political Report, Inside Elections and Sabato's Crystal Ball; it then adjusts that margin toward its estimate of the national political environment.
Equivalent Margin | |||
---|---|---|---|
Expert | Rating | Raw | Adjusted |
Cook Political Report | R+12.1 | R+11.4 | |
Inside Elections | R+12.1 | R+11.2 | |
Sabato's Crystal Ball | R+12.1 | R+12.5 | |
Average | R+12.1 | R+11.7 |
Nate Silver explains the methodology behind our 2018 midterms forecast. Read more …
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