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Chance the Democrat wins (>99.9%)
Chance the Republican wins (<0.1%)
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 haven’t been able to find any polls for this district. Know of one? Send us an email.
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.
|Karen Bass has been elected to 4 terms. Congress has only a 20.1% approval rating, reducing the incumbency advantage.|
|CA-37 is 70.8 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.|
|Incumbent's margin in last election|
|Bass won by 62.3 percentage points in 2016, but did not face major-party opposition.|
|Democrats lead by an average of 8.6 percentage points in polls of the generic congressional ballot.|
|As of Oct. 17, Bass had raised $463,000 in individual contributions (99% of all such contributions to the major-party candidates); Ron Bassilian had raised $5,000 (1%).|
|Incumbent's voting record in Congress|
|Bass has voted with Democrats 96% 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.|
|Bassilian has never held elected office.|
|Neither candidate is involved in a scandal.|
|Top-two primary margin|
|Democrats won the aggregate vote by 78.4 percentage points in the June primary. However, turnout patterns can differ in the general election, so the model compares the primary result to others in California. On that basis, it treats the primary result as equivalent to a 92.0-point win for Democrats.|
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||D+81.3||D+81.9|
|Sabato's Crystal Ball||D+81.3||D+80.9|
Nate Silver explains the methodology behind our 2018 midterms forecast. Read more …