It becomes much easier to understand when you realize that the modern Republican Party opposes centralized voter ID at the national level and supports stricter but wildly patchwork voting ID requirements at the local level for the same reason: it makes it harder for demographics they don't like to get acceptable IDs for voting.
For example, in 2015, North Carolina's Republican state legislature literally looked up the forms of ID statistically most likely to be used by black people for voting ID in the state and banned those for use in voting, while leaving the forms of voting ID most used by white people as valid. https://www.washingtonpost.com/news/wonk/wp/2016/07/29/the-s...
For example, in 2015, North Carolina's Republican state legislature literally looked up the forms of ID statistically most likely to be used by black people for voting ID in the state and banned those for use in voting, while leaving the forms of voting ID most used by white people as valid. https://www.washingtonpost.com/news/wonk/wp/2016/07/29/the-s...