Tuesday’s Democratic primaries in Massachusetts will likely determine the state’s congressional delegation for next year. With the state so Democratic, primaries are often more consequential than general elections. Senator Ed Markey, 80, faces a challenge from Representative Seth Moulton, 47, over generational change and Markey’s age.

Markey has defined himself as the progressive, citing endorsements from Bernie Sanders and Alexandria Ocasio-Cortez, and has avoided public senior moments unlike Biden or John Larson. Moulton, a Marine veteran, leads Serve America, which has flipped 24 seats and supports 23 current House members and 13 Democratic nominees this year. Representative Stephen F.

Lynch, 71, a moderate and the last House Democrat to vote against the Affordable Care Act, also seeks re-nomination. The winner of the Senate race will face Republican John Deaton, who earned 40% against Elizabeth Warren in 2024. The primaries will test whether Massachusetts Democrats favor experience or new leadership.