Are you familiar with the Southern Baptists? There are over fifteen millions members.
To be honest, I actually live in Florida, and attend a Baptist church! What a coincidence!. 
I live in Florida too! Although the "Southern" in Southern Baptist orginated in Georgia.
Technically, you could argue that Florida is more Northern than Southern, so I suppose that is fair.
Yes, we are pretty much South New York here lol. Although since the 1940's the SBC has shifted some of its regional identification.
Why do you suppose that is? The country culture was limiting its membership?
Some of it was a schism betwen liberal and conservative individuals, particulary a shift away from liberalism.