The pollsters do exit polls in areas that they consider bellweather districts. For the most part, they are fairly accurate. They wait until the polls close to tell their results. If its not close, I imagine that they know pretty early.
Rubio sounds like a petulant child
“we will not allow the party of Lincoln and Reagan to fall into the hands of a con artist!”
YOU HAVEN’T WON A SINGLE STATE YOU GREASY NASTY PIECE OF*****