Races · Senate · 2020 · Massachusetts

Senate · class II · open seat

Ed Markey vs Kevin O'Connor

← Louisiana Senate Maine Senate →

Safe DD +33.7 forecast· 4 polls · 0 markets

Model's final pre-election call · win probabilitypoliagg-v34 · final pre-election call
99% Markey (D)
1% O'Connor (R)
Win probability
Ed Markey99% (D)
Kevin O'Connor1% (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 +33.7
80% CID+21.7 → D+45.7
The model’s central margin (D-positive) with its 80% interval — the shaded band on the scale.
Model's predicted final margin D +33.7 · 80% CI D+21.7 → D+45.7
Actual result D+33.1 · 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

Likely D · model 99% D

No recent polls or markets for this race. PVI baseline (D+13) suggests Likely D.

The poliagg-v34 ensemble forecasts D+33.7 with an 80% CI ranging from D+21.7 (10th pctile) to D+45.7 (90th pctile), giving D a 99% chance of winning.

CITATIONS · likely-d

Forecast · poliagg-v34

Predicted final margin

D +33.7

80% CI: D +21.7 → D +45.7 · win prob 99%

R+60R+30TIEDD+30D+60

Quality · inputs

Data quality · medium

Polls used	4
Days to election	passed
Actual result	D+33.1
Residual σ	6.00pt
Generated	7/1/2026

Polling average

POLL DOTSCI BAND
253035404550556065MARKEY 62.3MARKEY 50.0O'CONNOR 40.0O'CONNOR 27.5SEP '20OCT '20OCT '20
Weighted, plus each pollster's measured bias subtracted before averaging.

All polls · 4 results

strongpositiveinfocautionflag

Date	Pollster · trust signals	n · pop	Lean	Bias · track	vs raters	D · R
Oct 29	MassINC+1	929 · LV	NEUTRAL	R +4.63 tracked	+3.6noisy	60 · 29
Oct 20	YouGov/UMass Amherst	713 · LV	NEUTRAL	—	—	65 · 26
Sep 16	Remington Research	907 · LV	NEUTRAL	—	—	50 · 40
Sep 15	Remington Research Group	907 · unknown	NEUTRAL	D +0.211 tracked	+1.6aligned	—

Endorsements · 0 total

Source · Wikipedia · 4 candidates with no endorsements yet

DEd Markey0 endorsers

no endorsers yet

No endorsements found yet. Endorsements come from the candidate's Wikipedia article (when one exists) and update with the daily scrape.

RKevin O'Connor0 endorsers

no endorsers yet

No endorsements found yet. Endorsements come from the candidate's Wikipedia article (when one exists) and update with the daily scrape.

DEMEdward J. Markey0 endorsers

no endorsers yet

No endorsements found yet. Endorsements come from the candidate's Wikipedia article (when one exists) and update with the daily scrape.

REPKevin J. O'Connor0 endorsers

no endorsers yet

No endorsements found yet. Endorsements come from the candidate's Wikipedia article (when one exists) and update with the daily scrape.

Money raised · own committees

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

Ed MarkeyS4MA00028 ↗

Receipts

$11.8M

Disburse

$13.0M

Cash on hand

$1.6M

Debts

Top industries

Securities & investment$69.1K

Education$62.5K

Internet$35.4K

Health professionals$20.1K

Top contributors

WILMERHALE$47.1K

APOLLO GLOBAL MANAGEMENT$37.3K

GOOGLE$35.4K

HARVARD UNIVERSITY$34.7K

BLACKSTONE$31.8K

Kevin O'ConnorS0MA00232 ↗

Receipts

$947.0K

Disburse

$884.1K

Cash on hand

$63.0K

Debts

$267.8K

Top industries

No industry data.

Top contributors

CHEMGENES CORP.$13.4K

PAYFACTORS$7.1K

PMC$5.6K

BLUEFISHCAPITAL$5.6K

HARBOURVEST$5.6K

Outside spending · independent expenditures

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

IE total

$10.9M

D side

$10.9M · 100%

R side

$0 · 0%

Top spender

UNITED FOR MASSACHU…

For / against split

For Markey $10.9M

Against O'Connor $115.05

Spender	Side	Amount	Share	Target
UNITED FOR MASSACHUSETTS	D	$10.0M	91%	for Ed Markey
ENVIRONMENT AMERICA ACTION FUND	D	$615.4K	6%	for Ed Markey
INDIVISIBLE ACTION	D	$293.1K	3%	for Ed Markey
CHINESE PROGRESSIVE POLITICAL ACTION IE PAC	D	$17.9K	0%	for Ed Markey
PLANNED PARENTHOOD VOTES	D	$115.05	0%	against Kevin O'Connor

Editorial ratings · 5 raters

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

Safe D5

The Cook Political Report

Safe D

Oct 28

DDHQ

Safe D

Nov 2

538

Safe D

Nov 1

Inside Elections

Safe D

Oct 27

Sabato's Crystal Ball

Safe D

Nov 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 verified3 / 4deterministic

Polls flagged—none

Markets ingested0 platformsnone listed

FEC filingssyncedcommittee + IE · 2020-11-20

Endorsements—nothing to sync

News coverage< 5 articlesGoogle News

Method · bounds + percentage totals + date-order checks