Political scientists at Harvard said Democratic victories in last week’s off-cycle elections were a sign of powerful backlash to Donald Trump’s presidency, but that Democrats could not afford to rest on their laurels ahead of the 2026 midterms. Tuesday’s elections added new fuel to debates over whether Democrats could best strengthen their coalition by shifting to the center or embracing their party’s left wing. Moderates Sherrill and Spanberger wielded their congressional experience and military and intelligence backgrounds to win governor’s seats. But Mamdani secured the New York City mayor’s office after running an unapologetically progressive campaign. Some Harvard faculty said...