Inconsistent access and inconsistent standards, for the most part.

A classic example is how certain states (Texas, for instance) will assert that gun licenses qualify as a valid ID but state university student IDs will not. Another is in how IDs - like driver’s licenses - have a fee associated with registration and renewal, which amounts to a poll tax. A third is that citizenship isn’t necessarily a prerequisite for voting in municipal and state elections. So requiring someone to be a citizen before accessing a ballot becomes an unconstitutional burden at the state and local level.

Then there’s the fact that we already have a voter id system. It’s called your voter registration card. You typically get one after you’ve registered to vote in your municipality. The fight over voter ID is that you need a second piece of identification on top of the registration card.

Broadly speaking, if everyone was afforded equal access to a single uniform ID document at no cost, there wouldn’t be a problem. But so much of the Voter ID rules don’t establish homogeneous ID requirements. Implementation is left up to the states. So states with a history of hostility towards democratic rule can back-door disenfranchisement into the process of obtaining these documents.