For the record, I loathe the ACLU because they, or at least the ones with whom I deal at the MT capitol building, lie and twist information regularly. As far as this article goes, I'd just ask this: What safeguard do they have in place to protect against fraud if there is no voter ID?
There is no good answer, because if you don't know who is voting then you can't protect against fraud, which is absolutely present in any election. Currently the levels of fraud are small, but removing safeguards removes any ability to tell if it grows and simultaneously emboldens those who would.
Additionally, the only thing preventing 100% distribution of free ID cards is a state legislature and money. We are the wealthiest country on the planet; initiating a Federal program to fund and expand the ID apparatus of each state would be trivial from a cost concern and reap all sorts of useful benefits. With expanded office locations for distribution points you could not only take an easy step towards securing voting, but also encourage more people to participate in all the other great things you can do with ID's (drive, buy alcohol, get a passport to travel, etc).
There is literally no downside to expanding ID access, and a lot of downsides to removing the need for it.