Incumbent Democrat Ed Markey holds a narrow lead over Representative Seth Moulton in the latest Emerson College poll of the September 1 Democratic primary, with 37% to 32% among likely voters amid high undecideds, bolstering trader consensus on a Democratic general election victory in deep-blue Massachusetts. The state, which last elected a Republican senator in 1978, features limited GOP infrastructure and a presumed nominee in Marine veteran John Deaton, who previously ran unsuccessfully. Markey's long incumbency since 1977, recent progressive endorsements from groups like Sunrise Movement, and historical 66% win in 2020 underpin the 94.5% implied probability for Democrats, though a major scandal, nominee health issues, or national Republican midterm wave could narrow the path despite structural advantages like strong turnout in urban areas and no competitive battleground dynamics.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · UpdatedMassachusetts Senate Election Winner
Massachusetts Senate Election Winner
$12,965 Vol.
$12,965 Vol.

Democrat
95%

Republican
4%
$12,965 Vol.
$12,965 Vol.

Democrat
95%

Republican
4%
A candidate shall be considered to represent a party in the event that he or she is the nominee of the party in question. Candidates other than the Democratic or Republican nominee (e.g., Greens, Libertarian, independent) may be added at a later date.
Candidates who run as independents will not be encompassed by the “Democrat” or “Republican” options regardless of any affiliation they may have with the party.
The resolution source for this market is the Associated Press, Fox News, and NBC. This market will resolve once all three sources call the race for the same candidate. If all three sources haven’t called the race in this state for the same candidate, this market will resolve based on the official certification.
Market Opened: Oct 13, 2025, 5:07 PM ET
Resolver
0x2F5e3684c...A candidate shall be considered to represent a party in the event that he or she is the nominee of the party in question. Candidates other than the Democratic or Republican nominee (e.g., Greens, Libertarian, independent) may be added at a later date.
Candidates who run as independents will not be encompassed by the “Democrat” or “Republican” options regardless of any affiliation they may have with the party.
The resolution source for this market is the Associated Press, Fox News, and NBC. This market will resolve once all three sources call the race for the same candidate. If all three sources haven’t called the race in this state for the same candidate, this market will resolve based on the official certification.
Resolver
0x2F5e3684c...Incumbent Democrat Ed Markey holds a narrow lead over Representative Seth Moulton in the latest Emerson College poll of the September 1 Democratic primary, with 37% to 32% among likely voters amid high undecideds, bolstering trader consensus on a Democratic general election victory in deep-blue Massachusetts. The state, which last elected a Republican senator in 1978, features limited GOP infrastructure and a presumed nominee in Marine veteran John Deaton, who previously ran unsuccessfully. Markey's long incumbency since 1977, recent progressive endorsements from groups like Sunrise Movement, and historical 66% win in 2020 underpin the 94.5% implied probability for Democrats, though a major scandal, nominee health issues, or national Republican midterm wave could narrow the path despite structural advantages like strong turnout in urban areas and no competitive battleground dynamics.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · Updated



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