It makes sense from one perspective :
A significant issue stirring Republican Party angst over illegal immigration concerns sanctuary cities/towns. However, Martha's Vineyard does not have any sanctuary towns. Those 50 immigrants were simply relocated from a location which wasn't a sanctuary city, and transported to a location that was. If DeSantis was truly interested in making a point against sanctuary cities, then those 50 immigrants would have been taken to Boston in the first place (an actual sanctuary city).