Spanish for "voter registration" is...

[skids]

"papeles de votación"

Or more colloquially, it can be phrased "papeles para votar" ("papers to vote")

If you don't know why you needed to know that, browse around, you'll know soon enough.

It might also be a good time to remember that the German words for Perch and Large Mouthed Bass are very similar, because you will probably want to use dubya's fish story as a followup example should you have the occassion to use the above gem of knowlege.