Kyle Rittenhouse, the 17-year-old charged with fatally shooting two people and injuring a third during unrest last month in Kenosha, has become a cause célèbre among conservatives and some gun-rights groups. On Thursday night, his mother and lawyer got a standing ovation at a Waukesha County Republican event after their introduction by conservative commentator Michelle Malkin. The teen has even become a symbol in Europe; fans of a Bulgarian soccer team displayed a banner saying he "did nothing wrong ... he is a hero" at a recent match. His lawyers have talked widely about his case and even played a...