ID to Vote

Lot's of talk about needing to produce a valid ID in order to vote. My question is why have we waited so long to do this? We should do everything possible to secure the validity of every election and it seems logical to only have people vote that are supposed to and to ensure that we only get one vote.
I have heard opposition saying it is discrimination, too whom I'm not sure. Even in Iraq they dip a finger in blue ink to make sure no one votes twice.
What would it take to do this? First everyone would need a valid ID and if they needed one and could not afford the cost it should be free.
Then no ID means no vote. This stops people from voting more than once and it stops those that are not citizens from voting.
I think it is time that We The People have the most secure elections possible. If you disagree please educate me to your views.