By Daniel Kline Las Vegas isn’t called Sin City for no reason. And some of the sin has been missing due to the Covid pandemic. Las Vegas has already begun its comeback from the pandemic. Executives at both Caesars Entertainment (CZR) – Get Caesars Entertainment Inc Report and MGM Resorts International (MGM) – Get MGM Resorts International Report have said that booking trends have picked up, and anecdotal online evidence suggests a busy March Madness season at casinos both on The Strip and on Fremont St. downtown. Nicknamed Sin City, Las Vegas has always been about excess. That might mean gambl…