Polling Average
80%60%40%20%0%
55.9%
29.7%
Democrat
David Allen Costello
Democratic candidate for U.S. Senate in Maine
Maine Democratic Senate nominee?
$6.1M
JUN 10, 2026Primary Election
Party selects its nominee.
Live Odds
Current prediction-market probability for the candidate, updated as market prices change.
David Allen Costello is trading at 1% to win the Maine Democratic Senate nominee? on prediction markets.
Candidate Overview
Key details about the candidate’s background, party, office sought and current campaign.
Current roleGovernment/public-sector administrator
PartyDemocratic
Political ideologyProgressive Democrat
LocationMaine
BackgroundGovernment/public-sector administrator
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EducationOld Town High School (graduate)
Notable personal detailsDavid Allen Costello is a Democratic candidate for U.S. Senate in Maine. He has worked in senior-level government and public-sector roles, including with USAID and in Maryland state government. He is a graduate of The George Washington University (B.A. in Political Science and History) and the London School of Economics (M.S. in Government/Political Sociology). He is based in Brunswick, Maine.
SourcesShowHide
pressherald.comballotready.orgcostelloforsenate.comtownofwhitefield.combrunswickme.govwashingtonpost.compredictionedge.comags.hawaii.govclerk.house.govgopknoxcounty.compreblestreet.orgdocuments.adventistarchives.orgivoterguide.comidcrawl.comfalmouthme.orgtownofnorthberwick.orgfreepeoplesearch.comballotwire.comreddit.comarxiv.orgwmtw.comontheissues.orgdemocracyinaction.usmainemorningstar.comfec.govpoliticspa.commainepublic.orgabc3340.comnbcnews.comballotpedia.orgfacebook.comwashingtontimes.comnpr.orgen.wikipedia.orgdeveloper.ballotpedia.orglegislation.ballotpedia.orgapi.open.fec.gov
Political Positions
LiberalConservative
Economy & Taxes
Supports increasing taxes on wealthy individuals and corporations, expanding tax credits and incentives for low- and middle-income people and small businesses, and using tax changes to fund expanded government programs and investments (infrastructure, R&D, housing, Social Security/Medicare protection). Advocates a global minimum corporate tax and reallocating subsidies from large agribusiness and fossil fuels to rural and clean-energy initiatives.
Healthcare
Supports expanding access to government-provided coverage by offering Medicare (including dental and vision) to anyone who wants it, improving the Affordable Care Act for those who do not enroll in Medicare, and increasing funding for substance use and mental health services.
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Immigration & Border
Supports comprehensive immigration reform that secures borders while facilitating legal immigration and addressing worker shortages; emphasizes enactment of reforms to expand legal pathways alongside border security measures.
Abortion & Reproductive Rights
Supports protecting women’s reproductive rights, including codifying Roe v. Wade and increasing funding for organizations like Planned Parenthood. Backs actions to protect reproductive health decisions and broader civil rights protections.
Climate & Energy
Supports an aggressive, science-based national climate action plan with strict greenhouse gas emissions caps, large clean energy and efficiency investments, GHG sequestration goals, and reallocation of fossil-fuel subsidies toward clean energy. Backs policies such as a carbon tax and expanded renewable development (wind, solar, hydro) while urging protections for affected communities and fisheries.
Public Safety & Guns
The candidate supports stronger federal gun safety laws including universal background checks, safe storage requirements, bans on military-style/assault weapons, red flag measures, and increased funding for mental health and community policing; he also supports stricter sentencing for gun-related crimes while saying he would not deny responsible citizens the right to own guns.
Latest News
AINews Summary
Last updatedJul 17, 2026
David Allen Costello is one of the Democrats competing in Maine’s crowded 2026 Senate primary, which is now focused on choosing a replacement nominee after Graham Platner withdrew. The party is set to pick its nominee at a July 25 convention, and candidates have already begun debating and positioning themselves for the race against Republican Sen. Susan Collins. Costello has also been noted for highlighting endorsements from lobbyists as he campaigns.
pressherald.com+36
Articles
TNThe New York Times29 days ago
5 Takeaways From a Maine Debate That Showed Replacing Platner Isn’t Easy
Neutral
BDBangor Daily News4 months ago
Pine Tree Results PAC attacks Graham Platner
Neutral
WEWashington Examiner29 days ago
Populist Maine Senate hopeful touts endorsements from lobbyists
Neutral
BDBangor Daily News4 months ago
Donald Trump’s low Maine approval is making things hard for Susan Collins
Neutral
Latest Polls
Recent polling results and the candidate's current average in the race.
David Allen Costello currently averages 1.9%, ranking third in this race, 27.8 points behind the next candidate.
Polling average: 1.9%Position: thirdMargin: -27.8 ptsLatest poll: 5.0% (Jun 5 - 5)Polls included: 10
Average recalculated from polls through Jun 5 - 5.
Aggregation source: FiftyPlusOne
Campaign Fundraising
Latest report: Cycle 2026Campaign finance totals from the latest available reporting period.
Total raisedCash on hand
$154.4K
$115.8K
$77.2K
$38.6K
$0
2024
2026
LatestYear
Total raised
Cash on hand
Total spent
Burn rate
Cycle 2024
$111.3K
$0.00
$111.6K
$4.7K
Cycle 2026
$154.4K
$18.1K
$136.3K
$7.6K
Source: FEC
New updates coming soon
We're monitoring and will update when new data impacts the race.
- Endorsements