What ID is needed to travel by air domestically in the US?

Not: What ID is needed to travel by air domestically in the US?
What ID should one show when travelling/buying air tickets in the US? What if the ID is an expired driver’s licence, will that person be able to travel domestically or not? What IDs can be used?

Answers and Views:

Answer by rickbrowntravels.com
A valid state or government issued ID.

Answer by Jerry B
You can still travel with an expired drivers license but you will go thru extra screening when you check in at the airport and go thru the security checkpoint.

Answer by Mocha
For domestic travel a photo ID like your Drivers License is adequate. However it is advisable to also carry your passport in case you are required to prove that you are a US citizen.