That being said, buying certain over the counter medication requires a ID in grocery stores. Buying alcohol requires an ID in grocery stores. And dozens of other very common things that people do, require an ID.
Technically, those things require you to be over 18 (or 21, in the case of alcohol). There's no ID requirement if the person is over 18/21, it's just to confirm that they are of age. If the person looks to be 40, no rational checkout person is going to card them, unless mandated by some arcane CYA policy from the store.
An ID requirement is like, what you have for getting car insurance, or buying a firearm. You have to show an ID so that you can show proof of your name/address, or crap that has to be photocopied/documented for legal reasons.
EDIT: Oh, and I'll add, this was said by Trump specifically referencing increasing voter ID requirements, aka actually showing an ID for a purpose that required an ID, not just to confirm age or whatever. There's a very,
very clear distinction between getting carded for booze/death sticks/meth ingredients vs voter ID requirements. He was drawing a false equivalency (and an incorrect one at that... more like a 'not even wrong equivalency').