These Are the Mistakes Democrats Don’t Want to Repeat in 2020. Presidential Election of 2020, Presidential Election of 2016, Democratic Party, Michigan, Pennsylvania, Wisconsin, Biden, Joseph R Jr, Clinton, Hillary Rodham, Gillibrand, Kirsten E, Harris, Kamala D, Houlahan, Chrissy, Klobuchar, Amy, Pocan, Mark, Rendell, Edward G, Schatz, Brian, Warren, Elizabeth