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Massachusetts 3rd
Solid D
>99 in 100
Chance the Democrat wins (>99.9%)
<1 in 100
Chance the Republican wins (<0.1%)
Forecasted turnout
Partisan lean
# How the forecast has changed
We'll be updating our forecasts every time new data is available, every day through Nov. 6.
Chance of winning
Popular vote share
# What goes into the classic forecast in the Massachusetts 3rd
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.
—
Adjusted polls
D+38.3
CANTOR
D+31.5
Fundamentals
D+32.7
Experts
D+38.3
Lite
D+32.2
Classic
D+32.4
Deluxe
<0.1
<0.1
Historical adjustment
Key
More weight
Less
#Latest polls
We haven’t been able to find any polls for this district. Know of one? Send us an email.
Our latest coverage
#Similar districts and CANTOR
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.
Districts most similar to the Massachusetts 3rd
| Sim. score | Polling avg. | ||
|---|---|---|---|
| MA-2 | 76 | — | |
| NY-20 | 68 | — | |
| CT-1 | 67 | — | |
| RI-1 | 64 | — | |
| MA-8 | 63 | — | |
| MA-4 | 63 | — | |
| MA-6 | 63 | — | |
| RI-2 | 61 | — | |
| MA-1 | 61 | — | |
| MA-9 | 61 | — |
#The “fundamentals”
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 |
|---|---|---|
| District partisanship |  18.8 | MA-3 is 23.9 percentage points more Democratic-leaning than the country overall, based on how it has voted in recent presidential and state legislative elections. It voted for Clinton in 2016 and Obama in 2012. Massachusetts has been considerably more Democratic in state legislative elections than in presidential elections. |
| Previous incumbent's margin in last election | 2.4 | A Democrat won by 37.5 percentage points in this district in 2016. Previous district results are not strongly predictive in races without incumbents. |
| Generic ballot | 8.1 | Democrats lead by an average of 8.6 percentage points in polls of the generic congressional ballot. |
| Fundraising | 2.3 | As of Oct. 17, Lori Trahan had raised $1,393,000 in individual contributions (66% of all such contributions to the major-party candidates); Rick Green had raised $726,000 (34%). |
| Candidate experience | 0.0 | Neither Trahan nor Green has held elected office before. |
| Scandals | 0.0 | Neither candidate is involved in a scandal. |
| Total | D+31.5 |
#Expert ratings
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 | D+32.4 | D+33.0 | |
| Inside Elections | D+32.4 | D+33.3 | |
| Sabato's Crystal Ball | D+32.4 | D+32.0 | |
| Average | D+32.4 | D+32.7 | |
How this forecast works
Nate Silver explains the methodology behind our 2018 midterms forecast. Read more …
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