TSA takes on primary ID checks at airports

Here are more details about my observation that TSA is now doing the primary ID checks at airports:
September 26 was the first day that TSA took over the ID checking.
News reports suggested that the process can now take almost an hour since Transportation Security Administration agents took over the job of checking travel documents on Wednesday. Prior to the change, airlines checked passengers' identification. The TSA says it will do a more thorough job, causing longer delays at checkpoints. Passengers must still show their identification and tickets to security personnel, but the personnel are now government workers.
As I mentioned in an earlier post, this means that TSA is probably now enforcing the policies of the airlines (unless they are letting people fly without ID who haven't been approved by the airline). I worry that this may be unconstitutional.
Source 1. Source 2.