The fact that this is debatable shows the damage done to our public education system as we now appear to have an ever growing population of people who can't critically think. Citizens of the US have a representative republic. A representative republic means that duly elected officials represent the best interests of the citizens who elect them. Therefore the only people who should be represented are citizens of this country. Proving citizenship is not difficult (lest someone act as is disinfranchisement is a real thing). To get a State ID with a photo: if you were born in this country you need a birth certificate (available from your state govt for around $10) and 1-2 items showing your residence (a utility bill, your tax return, your selective service registration etc.). Naturalized citizens need the proof of residency and a green card. There is NO other country in which non-citizens are given a voice in the government. I can't go to Mexico and vote for their president or to the U.K. to vote for their PM. Why is that???