A Magic Poem Mystery

I found a box filled with notebooks and such from college. In my Math for the Liberal Arts binder I found several fun things (the perpetual calendar was one of those things), including a mysterious Magic Poem. It's so mysterious that I have no idea what it means anymore, and Google and Wikipedia were no help at all. Here's the poem (and yes, it's really all in caps):
( cut because it's kinda long )

I think the part underneath the dashed line tells how many of each letter is in the poem. Not every letter is represented, and the vowels aren't present at all. I also have no idea why the Ns are in bold, but they are. 'Tis a mystery...