Oh no, they are free - they're allowed to say literally anything, including garbage that would get you sued, beaten, or murdered if you were an individual saying it about any other 'non-notable' figure.

It's asinine that it was ever established law that the more 'public' a figure is, the more permissible it is to slander and defame them, to the point where you can literally claim anything about the president with zero repercussions.