What makes you think Cruz is going all out to win Florida? He should but that's not happening. He's fully understand that he will lose Florida. I can't tell that he even has a strong organization in FL.
Probably a rumor started by Trump backers to create some kind of atmosphere of rolling over the competition. I believe Trump will win Florida in a significant way. AFAIK, and can see locally, lots of union workers have changed party over the last few months to support Trump, whither they vote that way in the general is anybodies guess. Most probably see him as a Democrat that they could cast a vote for as a Republican as well, he has that dog whistle the Democrats can hear but many conservatives seem to be blind to. So it goes.
With a crazy socialist and an alcoholic criminal as their only choices, the Democrats have left their voters with little to choose from.
I’ve heard a couple of retired UAW boys that are big time Democrats and former Obama fans. They now call him things that would be fitting for a Klan rally.
They HATE the Clintons, know what a disaster Bernie would be, but they like American jobs, despise illegals and are now all in for Trump
Rubio will be strong in South Florida where he is from and will get a lot in the 1-4 corridor. The question is if Trump can get enough elsewhere in the state and be competitive with Rubio in places like the Orlando suburbs.