Republicans have not won a presidential election without Florida's electoral votes since Calvin Coolidge's win in 1924. We also helped the GOP squeak out the last two elections for Bush. So there's little arguing against the fact that for future Republican candidates, it's important that the Sunshine State at least be winnable, but recent voting trends show Florida drifting to the left.
Non-Cuban Hispanics now outnumber Cubans and might gravitate toward Democrats, and some theorize that even the Cuban population might become less monotonically Republican. Add to that the higher number of new Democratic registered voters and we're fixing for a generational shift in the way Florida votes.
Either Republicans figure out a way to win an election without Florida, or they need to stop the bleeding. Gerrymandering and a friendlier state party might keep congressional seats and the state legislature in play for a while longer, but unless they have a particularly popular candidate, it doesn't fair well if they have to play catchup here.