LANSING, Mich. — Fifteen years working as an emergency room nurse has convinced Kim Bogan that the only way to fix the American healthcare system is to tear it down and start over. Her patients arriving for triage are sicker than ever. They can’t afford many of the prescriptions they get in the ER. And sometimes when patients die, she wonders if she could have saved them had she not been caring for five or six other people at once. That’s why she spent the past year shuttling between 12-hour shifts at this city’s Sparrow Hospital and campaigning for Abdul El-Sayed, the Democrat who made...