Other posters pretty much covered most of the main ones. Cubans, oldies, it's all pretty cliché at this point really. Few more I think are worth adding:
1. Florida is one of the few remaining highly-urbanized states where people without a college degree (or a skilled trade with at least a few years of experience under their belt) have any level of economic mobility. Non-college people may be trending Republican nationwide, but this trend is largely driven by rural areas and small population centers. In most major metro areas, you're either a college grad in a very liberal white-collar bubble, or you're a non-college grad who's barely getting by and inclined to vote for the left. But Florida's economy is different than most heavily-urbanized states, in that it's less tech/STEM-heavy and offers more opportunities for non-college grads.
2. It's an attractive destination for conservatives. I think this narrative is exaggerated by terminally-online political nerds (so everyone on this site 
) because most people who move states do so for economic opportunities, not ideological motives. But there is a bit of self-selection in that Florida is one of the few places where the "Orange County Reaganite" lifestyle is still somewhat attainable. As for ideological motivation, DeSantis has given plenty of that, both in his culture war stances and approach to COVID.
3. It's a southern state, after all. Yes it's largely full of northeastern and midwestern transplants, but white Floridians with deep roots in Florida are southerners. There was still a Blue Dog element in rural Florida not too long ago, for example Bill Nelson did pretty well with them as recently at 2012. But at this point, Blue Dog Democrats have either been taken to the pound or are full-fledged Republicans now.
Good insight, especially the part about non-college grad economic mobility.
