DeSantis is 100% correct in what he said. And despite how the usual suspects would like to characterize this as him labelling all Trump supporters, that's not what he did.
There are people who support Donald Trump who nevertheless will disagree with him on specific issues, and are willing to state so publicly. There are some of those folks here.
But there are other Trump supporters who accept and agree with everything he says, not because that has always been their position, but simply because that's Trump's position. To the extent that describes someone, a "listless vessel" is a perfectly apt descriptor, though "mindless drones" or "adoring fanatics" (my personal preference) would be apt descriptors as well.