Ed Markey, the incumbent U.S. senator from Massachusetts who took office in 2013 after nearly 37 years in the House, faces a primary challenge from Representative Seth Moulton. Markey, who turned 80 in July and is seeking a third term, defeated Joseph Kennedy III in the 2020 primary by 55% to 45% and holds a majority endorsement from state Democratic delegates. Moulton, a six-term centrist congressman who briefly ran for president in 2020 and will turn 48 in October, has raised over $6 million compared to Markey's more than $8 million.