much like a lot of other areas of political analysis...i think people erroneously viewed a lot of what happened under obama as a guaranteed trend...instead of something that was largely endemic to him specifically.

in 2012 obama seemed to split the cuban fl vote (or even won it slightly). so i think people assumed repubs lost their grip on that demo and cubans were sliding into the dem category (along with every other latino group).

but then trump won low-50s percent of cubans. and repubs have still been winning them by the same recent majority margins they were before.

that could be viewed as obama fumbling away a group that was trending blue (cuban relationship thawing, end of wet foot dry foot, etc). or obama himself was just a unique candidate that appealed to swingy voters and young cubans (who helped tip the balance when they came out in greater numbers).

george w bush won like 75% of cubans in fl. and now repubs are only winning them at barely above 50% at the prez level. so its more likely that obama was just a temporary sharp/large peak among an ongoing consistent trend towards team blue.