Perhaps two of the most emotionally provocative people in the United States right now are Donald Trump and Adele. It makes sense, then, that the Donald uses Adele music at his rallies -- as AP News reported, "While waiting for Donald Trump to take the stage this week at a campaign rally in Exeter, New Hampshire, fans listened to a few hit songs by Adele, 'Skyfall' and 'Rolling in the Deep.'"
Politicians using music is nothing new -- Rick Perry, when he announced his campaign, used an abominable rap-country song to highlight his conservative values. The difference, though, is that good ol' Rick got permission before he used the song -- one of Adele's spokespeople said that "Adele has not given permission for her music to be used for any political campaigning."
However, the Donald is not violating any copyright rules -- and here lies an interesting schism in copyright law. Music performance and music distribution are treated as entirely separate, meaning that it's possible for me to obtain a license to make a video about Adele, but not perform the song live (and vice versa). The Donald has only been doing performances (meaning, playing from an iPod) of copyrighted music -- which is governed by performing rights groups such as ASCAP and BMI, which have contracts with artists and venues to allow songs to be played live at concert halls, public events... and rallies for the Donald.
Performance rights aren't even (generally) controlled by the artist, and instead are ruled by blanket licenses to venues. Distribution rights, though, are entirely different -- but still allow politicians to use some copyrighted works. While they can't directly distribute the work, they can, under the "Fair Use" doctrine, create parodies -- like the one the now-deceased Mike Huckabee made as a last-ditch effort to revive his campaign (fortunately for your ears, the video was removed by the former Huckabee campaign).
So sorry, Adele, Elton John, and all the other artists Trump and others are ruining. There may not be a lot you can do about it. Unless you wanted to tell Trump hello from the other side. Which I'd be welcome to.