I'd like to address your notion that legal - green card - aliens should be allowed to vote.

Tell me one country where legal immigrants who have NOT become residents of that country are allowed to vote in that country's elections.

The US is not alone in this way of thinking, although there are some countries that allow you to become a citizen of their country without renouncing your US citizenship - Ireland for one - if I understand their citizenship laws correctly.

Getting back to my original point, if an immigrant to the US wishes to exercise his "right" to vote in US elections, s/he must become a naturalized citizen, requiring seven odd years of residence in the US, after becoming a legal alien, i.e. green card - which are actually a pinkish purple, BTW. In some cases, military service in the US military can reduce this wait time to become a US citizen.

Dave