Describe Clinton/DeSantis/Scott voters

[Skill and Chance]

Yeah, the obvious answer is Cubans.

Cuban voters may not be voting Republican for President anymore, but they sure still vote R downballot.

In my humble opinion, we should wait until 2020 before making such predictions.

This. I think Cubans very well might come home in 2020; they seem to have warmed up to Trump.

Based on what? Has there been polling to substantiate this or is it just a gut feeling?

Also, while I do think it's plausible that Cubans will swing towards Trump if Sanders (especially) or Warren is the nominee, if it's Biden I highly doubt it. They will probably actually swing farther away from him, because Biden is a Catholic and will likely be seen as more moderate than Hillary; it will be very difficult for the GOP to paint him as a socialist, unlike Sanders.

Didn't Florida exit polls show Trump looking strong among Cubans last November?

Yeah. It seemed it wasn’t just anti-Trump Republican Cubans going back to vote for the GOP, it seems some actually warmed on him.

This.  Trump's approvals have been anomalously high in Florida compared to the other 2016 swing states.  I would not be surprised at all if it turns into a Bush 2004 level win for him.

[Skill and Chance]

This.  Trump's approvals have been anomalously high in Florida compared to the other 2016 swing states.  I would not be surprised at all if it turns into a Bush 2004 level win for him.

People keep saying this, but I don’t think the demographics are there for a Trump +5 win. He’ll be lucky to win Pinellas and Duval (Bush won the latter by 16% in 2004, which obviously isn’t replicable anymore), and he’s certainly not going to lose Miami-Dade by 6% like Bush did in 2004.

You're forgetting the retirement communities where Trump is going to get like twice as many votes as Bush did (both because they have dramatically grown and because the FDR-era retirees have mostly passed on).  It's basically the Republican version of "Emerging Democratic Majority."  The state is being swamped with near unanimous R wealthier than average retirees and the Caribbean Hispanic vote is not  really moving left.