Dear Democratic Party: You were the love of my life. I fell in love early and hard. I have been the kind of party loyalist ― the kind of sappy, soapbox-y, clichéd devotee ― that makes Fox News moonwalk with glee. The first vote I ever cast, at 18, was for Bill Clinton. The last vote I cast was for his wife, Hillary. My adoration for Hillary bordered on mania. In college, I named my ficus plant after her. Twenty years later, I canvassed, held fundraisers, dragged my 8-year-old daughter door to door, proudly wore HRC’s face on T-shirts and...