>99 in 100

Chance the Democrat wins (>99.9%)

<1 in 100

Chance the Republican wins (<0.1%)

us_map2See the national overview
Forecasted turnout
Partisan lean

# What goes into the
icon_classic_2
classic forecast in the California 30th

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+58.3

    CANTOR

  • D+54.3

    Fundamentals

  • D+55.0

    Experts

  • D+58.3

    icon_lite_2

    Lite

  • D+54.6

    icon_classic_2

    Classic

  • D+54.7

    icon_deluxe_2

    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 California 30th
Sim. score Polling avg.
CA-2866
CA-1161
CA-559
CA-5357
CA-2756
CO-153
IL-951
IL-1050
CA-1449
CA-4749

#The “fundamentals”

The Classic and Deluxe versions of our model use several non-polling factors to forecast the vote share margin in each district.

FactorImpactExplanation
Incumbency
1.8
Brad Sherman has been elected to 11 terms. Congress has only a 20.1% approval rating, reducing the incumbency advantage.
District partisanship
7.5
CA-30 is 36.0 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
11.4
Sherman won by 45.3 percentage points in 2016.
Generic ballot
3.9
Democrats lead by an average of 8.6 percentage points in polls of the generic congressional ballot.
Fundraising
7.1
As of Oct. 17, Sherman had raised $645,000 in individual contributions (100% of all such contributions to the major-party candidates); Mark Reed had raised $0 (0%).
Incumbent's voting record in Congress
1.5
Sherman has voted with Democrats 90% 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
0.4
Reed has never held elected office.
Scandals
0.0
Neither candidate is involved in a scandal.
Top-two primary margin
23.9
Democrats won the aggregate vote by 45.4 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 59.0-point win for Democrats.
Total
D+54.3

#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
ExpertRatingRaw Adjusted
Cook Political Report
Solid D
D+54.6D+55.2
Inside Elections
Solid D
D+54.6D+55.5
Sabato's Crystal Ball
Safe D
D+54.6D+54.2
AverageD+54.6D+55.0

How this forecast works

Nate Silver explains the methodology behind our 2018 midterms forecast. Read more …

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