Races · house · 2020 · Massachusetts

house · open seat

Katherine Clark vs Caroline Colarusso

← Massachusetts house Massachusetts house →

Safe DD +62.1 forecast· 0 polls · 0 markets

Model's final pre-election call · win probabilitypoliagg-v34 · final pre-election call
99% Clark (D)
1% Colarusso (R)
Win probability
Katherine Clark99% (D)
Caroline Colarusso1% (R)
Modelpoliagg-v34 · final pre-election call
Chance of winning across many simulations of the race — not projected vote share.
R+15R+5TIEDD+5D+15
Predicted margin
Point estimateD +62.1
80% CID+50.1 → D+74.1
The model’s central margin (D-positive) with its 80% interval — the shaded band on the scale.
Model's predicted final margin D +62.1 · 80% CI D+50.1 → D+74.1
Actual result D+48.7 · backtest (race already called)

Momentum

—

insufficient data

Tipping-point P

0.0%

Decisive for chamber control

Market · D-side

—

Cross-platform consensus

News articles · 30d

—

no recent coverage

Where this race stands

Verified

Safe D · model 99% D

No recent polls or markets for this race. PVI baseline (D+24) suggests Safe D.

The poliagg-v34 ensemble forecasts D+62.1 with an 80% CI ranging from D+50.1 (10th pctile) to D+74.1 (90th pctile), giving D a 99% chance of winning.

CITATIONS · safe-d

Forecast · poliagg-v34

Predicted final margin

D +62.1

80% CI: D +50.1 → D +74.1 · win prob 99%

R+100R+50TIEDD+50D+100

Quality · inputs

Data quality · medium

Polls used	0
Days to election	passed
Actual result	D+48.7
Residual σ	6.00pt
Generated	7/1/2026

Endorsements · 35 total

Source · Wikipedia · 0 candidates with no endorsements yet

32Clark · 91%
Colarusso · 9%3
Endorsements tracked
Katherine Clark32 · 91%
Caroline Colarusso3 · 9%
Total35
Scraped from each candidate’s Wikipedia endorsement list.

DKatherine Clark32 endorsers

Most notable · Elizabeth Warren · U.S. senator from Massachusetts

Other14

Organizations10

Elected officials6

Federal 3State 2Local 1

Newspapers2

RCaroline Colarusso3 endorsers

Most notable · Charlie Baker · governor of Massachusetts (2015–present)

Elected officials1

Federal 0State 1Local 0

Organizations1

Other1

Money raised · own committees

FEC Schedule E (independent expenditures) + candidate-committee totals · last filing 2020-11-20

Katherine ClarkH4MA05084 ↗

Receipts

$1.8M

Disburse

$1.5M

Cash on hand

$1.3M

Debts

Top industries

No industry data.

Top contributors

No contributor data.

Caroline ColarussoH0MA05132 ↗

Receipts

$152.3K

Disburse

$150.6K

Cash on hand

$1.7K

Debts

Top industries

No industry data.

Top contributors

No contributor data.

Outside spending · independent expenditures

FEC Schedule E (independent expenditures) + candidate-committee totals · 24/48-hr IE reports

IE total

$1.7K

D side

$1.7K · 100%

R side

$0 · 0%

Top spender

AFT SOLIDARITY

For / against split

For Clark $1.6K

Against Colarusso $115.05

Spender	Side	Amount	Share	Target
AFT SOLIDARITY	D	$1.5K	86%	for Katherine Clark
PLANNED PARENTHOOD VOTES	D	$230.1	13%	for Katherine Clark
SIERRA CLUB INDEPENDENT ACTION	D	$10	1%	for Katherine Clark

Editorial ratings · 3 raters

Cook · Sabato · Inside Elections · 538 · DDHQ et al.

Safe D3

The Cook Political Report

Safe D

Jul 1

Inside Elections

Safe D

Jun 1

Sabato's Crystal Ball

Safe D

Jul 1

Demographic crosstabs

age · education · race · gender

No demographic crosstabs published for this race yet. Most pollsters release only topline numbers; subgroup breakdowns (age, education, race, gender) appear here when a pollster publishes them.

Rating timeline

May 11, 2026Safe Dmodel

Verification trail

Polls verified0 / 0deterministic

Polls flagged—none

Markets ingested0 platformsnone listed

FEC filingssyncedcommittee + IE · 2020-11-20

Endorsements35 totalWikipedia scrape

News coverage< 5 articlesGoogle News

Method · bounds + percentage totals + date-order checks