As Americans fought in recent weeks over whether restaurants should refuse to serve top aides to President Trump, an entire city has been debating what it means to host his convention for reelection. Charlotte won the rights to the 2020 Republican National Convention on Friday. But that's largely because it faced little serious competition. And even before the victory was announced in Austin, Texas, this thriving, progressive urban island in the Trump-friendly South was suffering some buyer's remorse. Charlotte Mayor Vi Lyles, a Democrat, says the decision to host the convention was the hardest she has tackled — "not just...