Maybe not the margarita capital of the free world but in San Antonio Texas there is the river walk.
Lined with hotels and Mexican restaurants. One I have come to love but not been to in years is the Rita's.
Good Mexican food, I like their fajitas but that's not the main attraction.
It is their margaritas, a full menu of them. Some are made with 4 different top shelf tequilas and premium mixers etc.
The whole town had either monthly or weekly contests for the best margarita at the walk.
It is very serious for the bartenders and venues.
Up and down the walk I troll the best. At times some were very fruit laden with orange, limes, not sure what all but very refreshing in the San Antonio heat during the day.
If you have a sissy margarita lunch / early afternoon when it's blazing hot is a good time.