Does what DeSantis has done rise to the level of domestic terrorism? If we’re dreaming, freezing the finances of a known terrorist organization is a relatively standard practice isn’t it? Imagine if his campaign was completely unable to spend or receive donations.
Summarizing (as a layman, not a lawyer) the definition of domestic terrorism from the US code, his actions took place in the territory of the United States. It seems pretty clear (from DeSantis’s statements) that his actions were an attempt to influence government policy. That leaves whether his actions were illegal and risked injury or death to people.