In the wake of the riot on Capitol Hill on Jan. 6, 2021, a groundswell built in Washington to rein in the onslaught of lies that had fueled the assault on the peaceful transfer of power.Social media companies suspended Donald J. Trump, then the president, and many of his allies from the platforms they had used to spread misinformation about his defeat and whip up the attempt to overturn it. The Biden administration, Democrats in Congress and even some Republicans sought to do more to hold the companies accountable. Academic researchers wrestled with how to strengthen efforts to monitor…