If the Trump campaign paid royalties for the use of that song -- or ANY song -- they have the right to play it however they see fit. It all depends on whether they paid the royalties or not.

I remember a similar case many years ago when Rush Limbaugh started each show and each hour segment with that tune he made famous. It was by some rock band that never went anywhere on the charts, but he liked the beat. The group sued to make him stop using "their" song, but he had paid the royalties and used it anyway, up until his final show.