Thanks to the high school students with whom I’ve shared the past six weeks as instructor of creative writing and residential adviser at a pre-college summer enrichment camp on the campus of Amherst College, and thanks more importantly to my willingness to let those students plug their iPods into the auxiliary socket and turn the volume to “max” when they are riding with me in one of the fleet of mini-vans we keep on hand for class activities, evening excursions, and other sundry errands, I have of late found myself taken by the effortlessly relentless flow of a young MC from Pittsburgh by the name of Mac Miller. Just nineteen years old, Mr. Miller has not yet been signed to a major label, nor has he released a full-length album. By and large, he has made his name by way of what are called “mixtapes,” short compilations advertised by word of mouth and given away at concerts and online for promotional purposes, in the hope of eventually securing that coveted major label deal. For now, the majority of Miller’s fans are even younger than he is. But if you do not fit into that category there’s at least half a chance that you’ve heard a few bars of his “Donald Trump.” The hit song’s lyrics, coasting atop a catchy Saturday Morning Cartoons meets Sunday morning church chorus beat, include “I just wanna ride, ride through the city in a Cutlass/Find a big butt bitch, somewhere get my nuts kissed,” “I ain’t picky but these girls be acting tricky/When the situation’s sticky and the liquor got them silly,” as well as Miller’s rather inscrutable pledge, and apparent origin of the song’s title, to “take over the world when I’m on my Donald Trump shit.” I...