Massachusetts Democratic Senate primary sets up a battle of generations

By Alison Main, CNN (CNN) — Rep. Seth Moulton, a frequent critic of the old guard of Democratic leadership in Congress, is now taking on one of his party’s progressive stalwarts. The 47-year-old is running to unseat 80-year-old Sen. Ed Markey, who has represented Massachusetts in Congress since before Moulton was born. Markey, a longtime