What party is Thomas J. O'Brien?

Thomas J. O'Brien was elected as a Democrat; the office is elected on a partisan ballot.

Where does Thomas J. O'Brien stand politically?

There's no published left–right score for Thomas J. O'Brien. Most local officials have none: academic scores come from votes in Congress or a state legislature, or from campaign donors, and we don't guess.

Who is Thomas J. O'Brien? County Treasurer, Plymouth County

Thomas J. O'Brien is the County Treasurer, elected as a Democrat.

In office

Office	Who holds it now	Next term
County Treasurer · Plymouth County Treasurer	Thomas J. O'Brien Democratic source	On the Nov 3, 2026 ballot: count not certified yet

Plymouth County Treasurer's website (contact the office there) · everyone on it

Where Thomas J. O'Brien stands

No published left–right score. Most local officials don't have one: the academic scores come from votes in Congress or a state legislature, or from who donates to a campaign, and we don't guess. They were elected on a partisan ballot as a Democrat.

2026 election

Thomas J. O'Brien ran for Plymouth County Treasurer on the November 3, 2026 ballot. Their candidate page: campaign money, endorsements, opponents and results.

Quick answers

Who is Thomas J. O'Brien?: Thomas J. O'Brien is the County Treasurer, in Plymouth County, Massachusetts. Elected as a Democrat. The seat was on the November 3, 2026 ballot; the count isn't certified yet.
What party is Thomas J. O'Brien?: Thomas J. O'Brien was elected as a Democrat; the office is elected on a partisan ballot.
Where does Thomas J. O'Brien stand politically?: There's no published left–right score for Thomas J. O'Brien. Most local officials have none: academic scores come from votes in Congress or a state legislature, or from campaign donors, and we don't guess.

Are you Thomas J. O'Brien?

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Officeholders as of November 6, 2026, from the Secretary of the Commonwealth's certified election statistics (PD43+) of each seat's last election, and the county governments' own pages for their commissioners; officials appointed since an election may differ; each name links to its source. Officials change between elections (appointments, resignations), and the body's own website is the authority. Party is shown only for offices elected on a partisan ballot.

Plymouth County's elected officials

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