It is insanely popular in Mexico. Most matches are in Mexico City, although some are held in Tijuana (not far at all from San Diego, CA). While pro wrestling in the U.S. is dominated by the WWE (with upstart Orlando-based federation TNA trying to carve out their own part of the market), most of the lucha libre shown on Galavision is part of either the CMLL or AAA federations.
If you look at the audiences on these broadcasts, you will see a wide age range cheering: little kids, grandparents, multi-generational families, plenty of women along with all the men. The most popular star of lucha libre, El Santo (“The Saint”), was something of a folk hero in Mexico – he starred in movies (always in his trademark silver mask) as well as dominating the ring, and his image was licensed for all kinds of merchandise. Think of Hulk Hogan at the peak of his '80s popularity crossed with Elvis Presley to get some kind of idea of the El Santo phenomenon.