The Supreme Court recently ruled that state laws requiring government-issued photo ID to vote are constitutional. As Marie Cocco points out, these laws are mostly a blatantly partisan attempt by Republicans to disenfranchise democratic voters.
Let's start with the ideal. In this fantasy, there would be a national database. Each potential voter would present him or herself for identification (be it photo ID, fingerprint, retinal scan, or cheek swab), and then after verification, he or she would be allowed to vote. Registering for identification would be as simple as registering to vote, or as simple as getting a birth certificate. Every citizen would have the appropriate means of identification, at no charge and minimal inconvenience.
Now let's return to reality. Every voter does not have equal access. Government issued photo ID are expensive, and odds are if someone doesn't have the money to get them, he or she certainly doesn't have the time to jump through the necessary hoops to get one for free. Furthermore (which is why it always seems to be Republicans pushing for these laws), the voters most affected by these laws are likely to vote Democrat, making this far more about partisanship and far less about combating voter fraud.
So, ideally, should states require ID to vote? Yes. Given our current system of access to government identification, can we equitably require ID to vote? No.