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Chance the Democrat wins (6.7%)
Chance the Republican wins (93.3%)
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.
We've collected four polls for the Texas 31st. 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.
|margin||likely voter||Time-line||House effects||Adjusted margin|
|Siena College/New York Times||490||LV|
|Anzalone Liszt Grove Research|
|Public Policy Polling|
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.|
The Classic and Deluxe versions of our model use several non-polling factors to forecast the vote share margin in each district.
|John R. Carter has been elected to 8 terms. Congress has only a 20.1% approval rating, reducing the incumbency advantage.|
|TX-31 is 21.2 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. Texas has been considerably more Republican in state legislative elections than in presidential elections.|
|Incumbent's margin in last election|
|Carter won by 21.9 percentage points in 2016.|
|Democrats lead by an average of 8.6 percentage points in polls of the generic congressional ballot.|
|As of Oct. 17, Mary Jennings Hegar had raised $3,795,000 in individual contributions (83% of all such contributions to the major-party candidates); Carter had raised $754,000 (17%).|
|Incumbent's voting record in Congress|
|Carter has voted with Republicans 86% 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.|
|Hegar has never held elected office.|
|Neither candidate is involved in a scandal.|
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.
|Cook Political Report||R+12.1||R+11.4|
|Sabato's Crystal Ball||R+12.1||R+12.5|
Nate Silver explains the methodology behind our 2018 midterms forecast. Read more …