Voting especially during the two Bush elections became very important, down to a paltry few votes. So it is very important to make sure that the people that are voting are meeting the requirements of being a voter.
We require checks on whether someone is old enough to drink, but we don't make checks on voters. That doesn't make sense. We require people of all ages to have a social security number, and use it for many different areas beyond social security.
Even AAA won't believe that you are a member without showing your AAA card.
So why wouldn't it be necessary to check on voters.
Voting is not open to the public at large, there are requirements that must be met before you are allowed to vote.
How do we know if those requirements are being met by the hundred million voters? There is only one way, and that is to require identification. There is no privacy issue here of what and who they are voting for, only that they be qualified to vote.
There are over ten million illegal aliens in the country, so how do we know that they are not illegally voting?
Motivation for voting by those that are not legally permitted to vote is not the question. The question is whether they are voting or not voting in our elections?