By Marjorie Arons-Barron
Incumbency combined with voter inertia are a mighty force in keeping officials in office, be they high-performing or flawed. Nowhere is this truer than in down-ballot races, when all the excitement is at the top (e.g., the 2026 Democratic primary for U.S. Senate, the race for Massachusetts governor and controversial referenda (e.g., statewide rent control in the Commonwealth.) But less prominent down-ballot races are still critically important, notably the contest for Middlesex County District Attorney...