Every State in the US has ID cards, but citizens aren't required to obtain one at any point. (Although a heck of a lot of basic things-- driving a car on a public road, boarding an airplane, buying alcohol-- are gated by them.) What we don't have is a Federal ID card.

The TSA tried to impose one, but a lot of States are pushing back against it. (Washington State called the TSA's bluff and obtained a 2-year "extension" of our horrible awful non-TSA-approved satancards.) Even if the Feds succeed at requiring all State cards to feed into the same database, they have no power to require that every citizen obtain one.

The SSN was never intended to be ID, it's an account number. Anybody using it for ID is doing it wrong, but unfortunately, that's a heck of a lot of people.