Actually, they do ask for ID, but they still let all of us into the country. Here's how it works:

I'm on the watch list, so when I go into the airport they ask for my ID and then a big red light starts flashing on their screen. The man or woman behind the counter looks at me nervously and scribbles some symbol on my boarding pass.

Then they say "I'm sorry sir, but you've been randomly selected to undergo additional security screening procedures, could you please take your bags and step behind the curtain?"

They unpack all my stuff and wipe it down with a cloth to detect nitrates used in explosives, which people like me apparently use to blow up airplanes. Then they throw everything back ...

Actually, they do ask for ID, but they still let all of us into the country. Here's how it works:

I'm on the watch list, so when I go into the airport they ask for my ID and then a big red light starts flashing on their screen. The man or woman behind the counter looks at me nervously and scribbles some symbol on my boarding pass.

Then they say "I'm sorry sir, but you've been randomly selected to undergo additional security screening procedures, could you please take your bags and step behind the curtain?"

They unpack all my stuff and wipe it down with a cloth to detect nitrates used in explosives, which people like me apparently use to blow up airplanes. Then they throw everything back in the bag and check it in for me.

Then I go through security at the terminal, and they look at my passport and boarding pass and say "Oh, my." and then ask me to wait over there while one of the ladies calls for "Male Assist" (which is normally a gruff Marine-corps wannabe who asks me condescending questions and pats me down in a totally platonic way.)

Then I go to the departure gate and check in to the flight, and then they say "I'm sorry, sir, but we randomly select certain passengers for additional security inspection before boarding the plane, could you please step over here?"

Then I step aside and all my carry-ons are unpacked and searched and another middle-aged man with a buzz cut and doing his best R. Lee Emory impersonation looks suspiciously at my fountain pen and asks me what exactly I'm planning on doing with that?

Then a few hours later I repeat the process in reverse and and finally someone says "Welcome home Mr. Kramer." Because, after all, they can't stop me from entering the country because I haven't done anything wrong. All I did was major in International Studies with a focus on Islam, so they can't punish me (other than with airport delays) until I commit an actual crime, which of course I never do.

It's due process, sort of.