> What percentage of the population has an ID in a place where it's difficult to get one vs somewhere it is easier?

Not the OP, but except for passports (and passport cards)... there isn't really any federal-level ID in the US (and passport booklets/cards are expensive, just a bit over $100 IIRC).

The nearest equivalent in the state level are driver's licenses, which are also on the expensive side considering the ancillary costs (because it's a driver's license, not just an identification card). This is also the reason why US-centric companies like PayPal, for this exact reason, accepts a driver's license as proof of identification (obviously where not otherwise prohibited by local laws).

Some (New York for example) do have an ID (called a non-DL ID, that's how embedded driver's license is in the US), but most states do not have a per se ID.

> What constitutes an ID being expensive?

Developing countries, rather ironically, issue their IDs for free? Okay, indirectly paid by taxes, but there's no upfront cost. The above-mentioned identity documents have a clear cost attached to them.

> How is the rest of the world dealing with this problem? Do you think that their democratic processes might be compromised because of it?

Cannot talk about other countries (because there is an ID system and it's not a controversial affair to them), but instead I'll answer with a reflection of the US system.

Unfortunately, American ID politics are hard, mainly due to concerns of surveillance, but I think (only my opinion) because some of them want those historically disenfranchised (even if a fully native-born US citizen) de facto disenfranchised. This means that there is no uniform and freely-issued identification system in the US (or even a requirement to do that at the state level). Unfortunately, this... is a tough nut to crack, politically-speaking.

> most states do not have a per se ID

I haven't researched this thoroughly, but what state will not issue an ID that is equivalent in every way to a driver's license except that it isn't a license to drive? I just checked Mississippi, Wyoming, South Dakota, and West Virginia, all of which do, so clearly being rural, poor, or both isn't enough to stop states from doing it. (The detailed politics are, as you say, a mess.)

Note that drivers licenses wouldn't count as proof of citizenship under the SAVE act.

>but most states do not have a per se ID

Out of curiosity, do you have a source or list for this? My own home state and those around me that I've spot checked all have a state ID available as an alternative to a driver's license. My understanding was that this is the case for most states.

Unless I've misunderstood you and you meant a state ID that is completely separate from a driver's license to the point that people with a DL would have one?