It's no different than passengers going through screening - the TSA ID checkers aren't likely to catch a high quality fake ID, and we know that boarding passes can be faked. That's one of - if not the best - arguments as to why it's pointless for the TSA to be checking IDs anyway.

The point still stands though. A fake pilot in the cockpit is as dangerous as a passenger with grenades strapped to his chest. More so.

When you're sitting in the driver's seat, who cares if you have any weapon you want? Ergo, anything that can get you in the driver's seat should be good enough to get you past security, faked or not.

Taken to extreme it would be like the Secret Service checking the president for a swiss army knife before letting him into the big red button room.

So who does check the ID?

If it's not the super trained government appointed guardians of our safety - the clerk at the departure gate ?

Surely there should also be a TSA agent standing behind each pilot throughout the flight if they can't be sure of the pilots identity?

I flew yesterday, and arrived early enough to watch the crew get onto the plane. There was a cursory check of their IDs, but very cursory. The main thing seemed to be that everyone knew each other; the crew had worked together before, and the flight agent who checked their IDs knew them. I would not be surprised if the flight agent was given pictures of the pilots as well as their names, though, which would probably provide the greatest security (identity verified by a trusted third party, the airline, without any chance for the pilot to interact with the verifying document, as happens with passports or other ids. If you never get to see it, you can't tamper with it).

Except that in the US (unless you are at the airline's home base) the checkin+gate staff are probably on contract from some staffing agency or rented from the airport.

The 'Delta connection' flight you are on is sub-contracted out to a 2 man outfit with a single regional jet.

Pay and conditions are so poor that staff turnover is huge and the number of staff is reduced so that people barely have time to glance at the person.

It's one of the hidden costs of replacing the company security guard with the cheap outside agency.