We wanted to know: What’s the worst thing that could happen to our country during the presidential election? President Trump has broken countless norms and ignored countless laws during his time in office, and while my colleagues and I at the Transition Integrity Project didn’t want to lie awake at night contemplating the ways the American experiment could fail, we realized that identifying the most serious risks to our democracy might be the best way to avert a November disaster. So we built a series of war games, sought out some of the most accomplished Republicans, Democrats, civil servants, media...