I read a copy of the letter that this guy allegedly sent out and it says that it is a crime to vote only if you are not a US Citizen. The letter says that it is a crime to vote if you are an illegal alien or an immigrant. However, the context of immigrant appears to mean a legal resident who has not yet been naturalized. The letter says that only US citizens may vote which is accurate.
I think we can all agree that the wording in the letter is not the best.