There isn’t a Braves fanbase here. Local stations don’t broadcast their games (perhaps because TBS does), and there aren’t Braves caps on people on the street. There are significantly more transplanted Yankees, Indians and Red Sox fans around than there are fans of the Braves. Duke v. Carolina will always be more of a problem for a nascent baseball team here than encroaching on the Braves
In 2006, the city of San Antonio offered the Marlins a $240M package to relocate to San Antonio, but nothing much came of it. The offer was turned down, not because San Antonio wasn’t a viable market, but Marlins and MLB wanted to concentrate on getting a new stadium in south Florida for the team. I guess having the San Antonio option in their back pocket worked, because the Marlins now finally have their deal for a new Miami stadium.
The Astros are certainly the default team around here, but this doesn’t seem like much a baseball town. The local Texas League AA team has a long history but certainly doesn’t capture the love and the attention of the public the way the Spurs do. I’m sure it is a hard task to get people excited to “enjoy” 3 hours of South Texas summer weather even in the evenings, but a relocated MLB team would certainly require a retractable dome stadium like Houston’s.
Hard to say if a MLB team would attract the same long term support the Spurs have enjoyed. The Spurs have been lucky to have great teams and personalities like Gervin, Robinson, and Duncan over the years and that certainly is a major reason why this is a now a “basketball town”.
I compare San Antonio to Utah. The NBA is the only game in town. Salt Lake City is probably the most unlikely basketball city in the United States. But, the Jazz and the Spurs are the only major league franchises in town. They’ve both had success which helps.