Originally Posted by Often1

I doubt that TSA cares what you do or do not have for ID that is not presented at the checkpoint.

If you don't have compliant ID with you, you will be shunted off to the process for verifying your identity through secondary means.

My guess is that if there is still anybody out there lacking Real ID compliant (or other acceptable) ID if and when this all is effective, the identity verification process may be drawn out simply because of the numbers of people.