Exit polling will tell the experts who won Florida by about 7 p.m. EST. But the polls will be open on the West Coast for another four hours, and the TV people don't want to influence votes out there. It will be interesting to see what the networks do. Hold the news if Hillary wins Florida, because that means she's almost certain to be president? Release the news if Trump wins Florida, because that means he has a shot at winning?
They might do what's best for the nation, but they'll definitely do what's best for ratings.
The Real Clear Politics average has Trump +0.4, which means total tossup.