In Florida's case I think it's pretty simple: Miami. That city has a solid hispanic population that's growing heavily. Like I said in another thread it's not yet a situation where one city or area speaks for the whole state but if the Miami and Fort Lauderdale areas keep growing at their current pace it could get there in the next 20-30 years.
Looking at current growth rates, if St. Pete-Tampa, Orlando, Jacksonville, and Sarasota-Bradenton keep growing at the rates they're growing, yeah, South Florida'd be a bit bigger than all of em, but Miami is no Cook County, not for another 50+ years (might be a bit biased here, though, as a Tampa Bay-ian).