There are pundits like Damon Linker who want us to fear a Trump candidacy more than a DeSantis one. I fear DeSantis more. The problem for me with DeSantis is not that he will be more competent and effective authoritarian than Trump was--that's a toss-up. I fear him more than Trump because he's more electable than Trump will be in the general election.
If nominated, is there a risk Trump might win, yes, but it's very low, much lower than in '16. Why? Because then he was a blank screen onto which people could project their resentments. Now the general electorate knows too much about Trump for him to play the role of blank screen. Only the truly deluded and fanatical can vote for him, and while there are millions of them, there aren't enough to win in the swing states.
DeSantis will be for most swing voters more like Trump was in '16. He is now what Trump was then--a blank screen onto which they can project their resentments of the arrogant elite Liberal System that everyone despises, even Democrats. Conservatives will vote for him because he's on their team, and they hate Liberals, but the swing voters will vote for him because he seems "normal", especially compared to Trump.
But he's not normal; he's just a different kind of sociopath than Trump. "And besides," swing voters will reason, "We're tired of Trump, and we're tired of Biden. Let's go with someone new and young." On such thinking the future of American democracy likely depends.
In Trump v. Biden, Biden almost certainly wins. But DeSantis v. Biden? That's a matchup between democracy and authoritarianism that should really scare us.
[See Why I Prefer Trump 2 here.]