Open this photo in gallery: People walk outside the Fiserv Forum ahead of the 2024 Republican National Convention, in Milwaukee, Wis., on July 13.Alex Brandon/The Canadian Press As Republicans gather in Milwaukee for their national political convention in the wake of the attempt to assassinate former president Donald Trump, the United States faces two difficult questions, and the answers will define the country even as they illustrate the challenge facing its political class. In a presidential race that may have been altered in the long run, these two questions – thoroughly unanticipated as recently as halfway through the weekend, when...