Get more FiveThirtyEight
- Terms of Use
- Privacy Policy
- Your California Privacy Rights
- Children's Online Privacy Policy
- Interest-Based Ads
© 2018 ABC News Internet Ventures. All rights reserved.
Chance a Democrat wins (<0.1%)
Chance a Republican wins (>99.9%)
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+55.0
Adjusted polls
R+23.7
CANTOR
R+28.6
Fundamentals
R+37.6
Experts
R+39.3
Lite
R+38.0
Classic
R+37.8
Deluxe
<0.1
<0.1
Historical adjustment
Key
More weight
Less
We've collected one poll for the Louisiana 3rd. 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 | Methvin | Higgins | margin | likely voter | Time-line | House effects | Adjusted margin | |
Aug. 27-30 8/27-30 | Trafalgar Group | 1,417 | LV | 0.83 | 8% | 62% | R+54.0 | — | <0.1 | 1.4 | R+51.6 |
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. | ||
---|---|---|---|
LA-6 | 75 | — | |
MS-4 | 73 | R+12.4 | |
AL-1 | 71 | — | |
AL-3 | 70 | — | |
OK-4 | 67 | R+32.8 | |
MS-1 | 66 | R+24.5 | |
GA-3 | 62 | — | |
AL-2 | 61 | — | |
GA-1 | 61 | — | |
AL-5 | 61 | — |
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 | 2.8 | Higgins has been elected to 1 term. Congress has only a 20.1% approval rating, reducing the incumbency advantage. |
District partisanship | 11.6 | LA-3 is 35.2 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. Louisiana has been considerably more Democratic in state legislative elections than in presidential elections. |
Incumbent's margin in last election | 18.7 | Higgins won by 12.2 percentage points in 2016 in an open-seat race, but did not face major-party opposition. |
Generic ballot | 6.2 | Democrats lead by an average of 8.6 percentage points in polls of the generic congressional ballot. |
Fundraising | 8.0 | As of Oct. 17, Republicans had raised a weighted average of $480,000 in individual contributions (84% of all such contributions to the major-party candidates); Democrats had raised a weighted average of $90,000 (16%). |
Incumbent's voting record in Congress | 1.9 | Higgins has voted with Republicans 87% of the time in roll-call votes in recent sessions of Congress. Candidates who vote with their party very frequently tend to underperform at the ballot booth, other factors held equal. |
Challenger experience | 0.6 | As the incumbent, Higgins has held elected office before, but none of the other major-party candidates have. |
Scandals | 0.0 | None of the candidates are involved in a scandal. |
Number of candidates | 5.1 | In the Louisiana primary, the model gives a bonus to whichever party has more candidates running. In this district, Democrats have 4 candidates and Republicans have 2. |
Total | R+28.6 |
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+38.0 | R+37.3 | |
Inside Elections | R+38.0 | R+37.1 | |
Sabato's Crystal Ball | R+38.0 | R+38.4 | |
Average | R+38.0 | R+37.6 |
Nate Silver explains the methodology behind our 2018 midterms forecast. Read more …
Comments