On the Ballot: Markey-Moulton matchup underlines competing visions for change in Democratic Party

Rep. Seth Moulton and Sen. Ed Markey are squaring off for Massachusetts’s Democratic Senate nod next week in the latest primary to spotlight young challengers vying to push out the party’s old guard. Moulton, a 47-year-old who’s been in the House for six terms, is mounting a long-shot bid to unseat Markey, who at 80 has served on Capitol Hill for…