Even though we may debate the quality of the text (not high, in my opinion) the impact that this will have is undeniable.
The only question is if this impact will be as great in young voters as it will be in "pre-voters" and how far, demographically, stretches Eminem's fan base to have an impact in these elections as it will have on the youngsters opinion about this.
Aside all that, the video is an absolute piece of art. Fantastic.