In Florida, there were no Presidential primaries before 1972. The turnout in primaries has been spotty at best, with voter turnout not being more than 45% since 1980, the year that Reagan was in the race. In fact, the last primary where there were candidates running in both parties was 2008, with a turnout of 42%.
This year, turnout is estimated to have been 46%. That is more remarkable, considering that Republican turnout was 103,288 in Orange County, putting Republican turnout at 51.3%. Democrat turnout was 104,441, putting Democrat turnout at only 35.8%.
Trump seems to be energizing the Republican base. Hillary does not.