Election officials warned about poll watchers who had been steeped in conspiracy theories falsely claiming that then-President Donald Trump did not actually lose the 2020 election. Democrats and voting rights groups worried about the effects of new election laws, in some Republican-controlled states, that President Joe Biden decried as “Jim Crow 2.0.” Law enforcement agencies were monitoring possible threats at the polls. Yet Election Day, and the weeks of early voting before it, went fairly smoothly. There were some reports of unruly poll watchers disrupting voting, but they were scattered. Groups of armed vigilantes began watching over a handful of...