Races · house · 2020 · Maryland
house · open seat
Mia Mason vs Andy Harris
Where this race stands
VerifiedLikely R · model 99% R
No recent polls or markets for this race. PVI baseline (R+8) suggests Likely R.
The poliagg-v34 ensemble forecasts R+21.9 with an 80% CI ranging from R+34.0 (10th pctile) to R+9.9 (90th pctile), giving R a 99% chance of winning.
CITATIONS · likely-r
Forecast · poliagg-v34
Predicted final margin
R +21.9
80% CI: R +34.0 → R +9.9 · win prob 1%
R+45R+23TIEDD+23D+45
Quality · inputs
Data quality · medium
| Polls used | 0 |
| Days to election | passed |
| Actual result | R+27.0 |
| Residual σ | 6.00pt |
| Generated | 7/1/2026 |
Endorsements · 20 total
Source · Wikipedia · 1 candidate with no endorsements yet20
Endorsements tracked
Mia Mason20 · 100%
Andy Harris0 · 0%
Total20
Scraped from each candidate’s Wikipedia endorsement list.
DMia Mason20 endorsers
Most notable · Chris Van Hollen · U.S. senator from Maryland (2017–)
Other12
Other · 12
- 350.org
- Brady Campaign
- Brand New Congress
- College Democrats of America · Frostburg State University chapter
- Democracy for America
- Democratic Socialists of America · Metro DC chapter
- Jewish Voice for Peace · Action
- NARAL Pro-Choice America
- Neil Parrott · state delegate
- Our Revolution · Maryland chapter
- Sierra Club
- Universal Basic Income · rsal Basic Income activist
Organizations5
Organizations · 5
- Humane Society of the United States · Legislative Fund
- League of Conservation Voters · Action Fund
- National Education Association
- National Women's Political Caucus
- Planned Parenthood Action Fund
Elected officials3
Federal 2State 0Local 1
Elected officials · 3
- Chris Van Hollen · U.S. senator from Maryland (2017–)
- Pete Buttigieg · former mayor of South Bend, Indiana (2012–2020) and former candidate for 2020 Democratic presidential nomination .
- Andy Harris · incumbent U.S. representative
RAndy Harris0 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 2020-10-13Mia MasonH0MD01232 ↗
Receipts
$2.5K
Disburse
$0
Cash on hand
$0
Debts
$0
Top industries
No industry data.
Top contributors
No contributor data.
Andy HarrisH8MD01094 ↗
Receipts
$1.5M
Disburse
$983.3K
Cash on hand
$1.0M
Debts
$0
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 reportsIE total
$12.7K
D side
$12.0K · 95%
R side
$662.35 · 5%
Top spender
VOTE YES ON QUESTION 2
| Spender | Side | Amount | Share | Target |
|---|---|---|---|---|
| VOTE YES ON QUESTION 2 pac · boosts D
| D | $12.0K | 95% | for Mia Mason |
| HOUSE FREEDOM FUND pac · boosts R
| R | $662.35 | 5% | for Andy Harris |
Editorial ratings · 3 raters
Cook · Sabato · Inside Elections · 538 · DDHQ et al.Safe R3
Safe R · 3 raters
- The Cook Political Report · Jul 1
- Inside Elections · Jun 1
- Sabato's Crystal Ball · Jul 1
The Cook Political Report
Safe RInside Elections
Safe RSabato's Crystal Ball
Safe RDemographic crosstabs
age · education · race · genderNo 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
Verification trail
Polls verified0 / 0deterministic
Polls flagged—none
Markets ingested0 platformsnone listed
FEC filingssyncedcommittee + IE · 2020-10-13
Endorsements20 totalWikipedia scrape
News coverage< 5 articlesGoogle News
Method · bounds + percentage totals + date-order checks