Curiously, Arizona doesn't require physical documentation of the SSN; you simply need to know the number.

The thing that hangs me up is the requirement for two "documents or mail issued from a business, organization, tribal or government agency that contain both Applicant name and Current residential address". My residential address is not deliverable by the Postal Service. All mail from a "business, organization, tribal or government agency" is sent to our PO Box. Even the utility bills don't have the physical address (although the utility company obviously knows where we are).

Using my passport or GE card at the airport is far simpler than jumping through the 'Real ID' hoops.