Massachusetts held Democratic primary elections on Tuesday featuring a closely watched Senate contest between 80-year-old incumbent Sen. Ed Markey and 47-year-old Rep. Seth Moulton, reflecting a wider generational struggle within the party. Unusually, progressive figures are backing the older incumbent rather than the younger challenger, reversing the pattern seen elsewhere as Democrats grapple with age and leadership questions since Joe Biden's withdrawal from the 2024 presidential race.

Markey, a senator since 2013 after 37 years in the House, is supported by prominent progressives including Elizabeth Warren, Bernie Sanders and Alexandria Ocasio-Cortez, and is campaigning on issues such as the Green New Deal, Medicare for All and taxing billionaires. Moulton, a Marine veteran backed by New Jersey Governor Mikie Sherrill and endorsed by the Boston Globe, has made the case for age limits in politics central to his campaign, though he was forced to apologise during the race for earlier comments about transgender athletes in women's sport. Markey entered the primary as the clear frontrunner in polling and fundraising, with the winner set to face Republican John Deaton in the general election. The same ballot also features a six-way race to succeed Moulton in the House, primary challenges to several sitting Massachusetts Democrats, and a Republican gubernatorial primary to challenge Governor Maura Healey.