URBAN RENEWALS rarely trace their origins to Twitter, but then Miami is no conventional city. “How can I help?” Francis Suarez, Miami’s mayor, asked on Twitter in 2020, after a tech entrepreneur suggested moving Silicon Valley out of the Bay Area. Mr Suarez has an enthusiastic following as he tries to rebrand Miami from a party paradise into a hub for digital finance and technology. He even sports a T-shirt carrying a “#HowCanIHelp?” tagline.