Incumbent Democrat Bill Keating secured the nomination in the September 1 primary with roughly 77-80% of the vote against a single challenger, positioning him for a general election matchup against Republican Tyler MacAllister on November 3. The Massachusetts 9th District, covering Cape Cod, the Islands, and the South Shore, carries a consistent Democratic lean reflected in recent presidential margins and prior House results where Keating prevailed by double digits. Race ratings from multiple outlets classify the contest as Solid or Safe Democratic, supported by Keating’s established incumbency and fundraising edge. MacAllister, a local selectman and fisherman, advanced unopposed in the Republican primary but faces structural headwinds in a district where Democratic voter registration and turnout patterns have historically favored the incumbent. Late developments such as a major scandal, health event, or sharp national swing could narrow the gap, though none have emerged to date.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · UpdatedMA-09 House Election Winner
MA-09 House Election Winner
$23,264 Vol.
$23,264 Vol.
Nov 3, 2026
Bill Keating (D)
95%
Tyler MacAllister (R)
5%
$23,264 Vol.
$23,264 Vol.
Nov 3, 2026
Bill Keating (D)
$8,275 Vol.
95%
Tyler MacAllister (R)
$14,989 Vol.
5%
This market will resolve according to the party of the candidate who wins the MA-09 congressional district seat in the U.S. House of Representatives in the 2026 midterm elections. The midterm elections will take place on November 3, 2026.
A candidate's party will be determined by their ballot-listed or otherwise identifiable affiliation with that party at the time all of the 2026 House elections are conclusively called by this market's resolution sources. A candidate without a ballot-listed affiliation to either the Democrat or Republican parties will be considered a member of one of these parties based on the party with which they most recently expressed their intent to caucus at the time all of the House elections are conclusively called by this market's resolution sources.
This market will resolve based on the result of the election as indicated by a consensus of credible reporting. If there is ambiguity, this market will resolve based solely on the official results as reported by the United States government, specifically the Federal Election Commission (https://www.fec.gov/).Incumbent Democrat Bill Keating secured the nomination in the September 1 primary with roughly 77-80% of the vote against a single challenger, positioning him for a general election matchup against Republican Tyler MacAllister on November 3. The Massachusetts 9th District, covering Cape Cod, the Islands, and the South Shore, carries a consistent Democratic lean reflected in recent presidential margins and prior House results where Keating prevailed by double digits. Race ratings from multiple outlets classify the contest as Solid or Safe Democratic, supported by Keating’s established incumbency and fundraising edge. MacAllister, a local selectman and fisherman, advanced unopposed in the Republican primary but faces structural headwinds in a district where Democratic voter registration and turnout patterns have historically favored the incumbent. Late developments such as a major scandal, health event, or sharp national swing could narrow the gap, though none have emerged to date.
This market will resolve according to the party of the candidate who wins the MA-09 congressional district seat in the U.S. House of Representatives in the 2026 midterm elections. The midterm elections will take place on November 3, 2026.
A candidate's party will be determined by their ballot-listed or otherwise identifiable affiliation with that party at the time all of the 2026 House elections are conclusively called by this market's resolution sources. A candidate without a ballot-listed affiliation to either the Democrat or Republican parties will be considered a member of one of these parties based on the party with which they most recently expressed their intent to caucus at the time all of the House elections are conclusively called by this market's resolution sources.
This market will resolve based on the result of the election as indicated by a consensus of credible reporting. If there is ambiguity, this market will resolve based solely on the official results as reported by the United States government, specifically the Federal Election Commission (https://www.fec.gov/).
A candidate's party will be determined by their ballot-listed or otherwise identifiable affiliation with that party at the time all of the 2026 House elections are conclusively called by this market's resolution sources. A candidate without a ballot-listed affiliation to either the Democrat or Republican parties will be considered a member of one of these parties based on the party with which they most recently expressed their intent to caucus at the time all of the House elections are conclusively called by this market's resolution sources.
This market will resolve based on the result of the election as indicated by a consensus of credible reporting. If there is ambiguity, this market will resolve based solely on the official results as reported by the United States government, specifically the Federal Election Commission (https://www.fec.gov/).
Market Opened: Jan 28, 2026, 11:09 AM ET
Volume
$23,264End Date
Nov 4, 2026Market Opened
Jan 28, 2026, 11:09 AM ETResolver
0x2F5e3684c...This market will resolve according to the party of the candidate who wins the MA-09 congressional district seat in the U.S. House of Representatives in the 2026 midterm elections. The midterm elections will take place on November 3, 2026.
A candidate's party will be determined by their ballot-listed or otherwise identifiable affiliation with that party at the time all of the 2026 House elections are conclusively called by this market's resolution sources. A candidate without a ballot-listed affiliation to either the Democrat or Republican parties will be considered a member of one of these parties based on the party with which they most recently expressed their intent to caucus at the time all of the House elections are conclusively called by this market's resolution sources.
This market will resolve based on the result of the election as indicated by a consensus of credible reporting. If there is ambiguity, this market will resolve based solely on the official results as reported by the United States government, specifically the Federal Election Commission (https://www.fec.gov/).Incumbent Democrat Bill Keating secured the nomination in the September 1 primary with roughly 77-80% of the vote against a single challenger, positioning him for a general election matchup against Republican Tyler MacAllister on November 3. The Massachusetts 9th District, covering Cape Cod, the Islands, and the South Shore, carries a consistent Democratic lean reflected in recent presidential margins and prior House results where Keating prevailed by double digits. Race ratings from multiple outlets classify the contest as Solid or Safe Democratic, supported by Keating’s established incumbency and fundraising edge. MacAllister, a local selectman and fisherman, advanced unopposed in the Republican primary but faces structural headwinds in a district where Democratic voter registration and turnout patterns have historically favored the incumbent. Late developments such as a major scandal, health event, or sharp national swing could narrow the gap, though none have emerged to date.
This market will resolve according to the party of the candidate who wins the MA-09 congressional district seat in the U.S. House of Representatives in the 2026 midterm elections. The midterm elections will take place on November 3, 2026.
A candidate's party will be determined by their ballot-listed or otherwise identifiable affiliation with that party at the time all of the 2026 House elections are conclusively called by this market's resolution sources. A candidate without a ballot-listed affiliation to either the Democrat or Republican parties will be considered a member of one of these parties based on the party with which they most recently expressed their intent to caucus at the time all of the House elections are conclusively called by this market's resolution sources.
This market will resolve based on the result of the election as indicated by a consensus of credible reporting. If there is ambiguity, this market will resolve based solely on the official results as reported by the United States government, specifically the Federal Election Commission (https://www.fec.gov/).
A candidate's party will be determined by their ballot-listed or otherwise identifiable affiliation with that party at the time all of the 2026 House elections are conclusively called by this market's resolution sources. A candidate without a ballot-listed affiliation to either the Democrat or Republican parties will be considered a member of one of these parties based on the party with which they most recently expressed their intent to caucus at the time all of the House elections are conclusively called by this market's resolution sources.
This market will resolve based on the result of the election as indicated by a consensus of credible reporting. If there is ambiguity, this market will resolve based solely on the official results as reported by the United States government, specifically the Federal Election Commission (https://www.fec.gov/).
Volume
$23,264End Date
Nov 4, 2026Market Opened
Jan 28, 2026, 11:09 AM ETResolver
0x2F5e3684c...Incumbent Democrat Bill Keating secured the nomination in the September 1 primary with roughly 77-80% of the vote against a single challenger, positioning him for a general election matchup against Republican Tyler MacAllister on November 3. The Massachusetts 9th District, covering Cape Cod, the Islands, and the South Shore, carries a consistent Democratic lean reflected in recent presidential margins and prior House results where Keating prevailed by double digits. Race ratings from multiple outlets classify the contest as Solid or Safe Democratic, supported by Keating’s established incumbency and fundraising edge. MacAllister, a local selectman and fisherman, advanced unopposed in the Republican primary but faces structural headwinds in a district where Democratic voter registration and turnout patterns have historically favored the incumbent. Late developments such as a major scandal, health event, or sharp national swing could narrow the gap, though none have emerged to date.
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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