Native born Americans of non immigrant parents are incredibly afraid of the us government.
Growing up in a family that came to this country, you're very disabused of the notion these agents have much power.
For most of them it's a power trip. Once you understand that, you will figure out what to say.
You have to understand that they know they're lying to you but it makes them feel powerful. Play into it. Let them feel the rush of power but remain firm in your goals.
I know in developing countries, the cops are nothing more than opportunist thugs. I have friends who tell them to just "fuck off" regularly. Then they come to the US with the same attitude, and while true US cops have limited powers, the "fuck off" approach often doesn't go over as well as politely refusing and stating your rights.
When I was younger I used the "fuck off" approach. I would say it worked slightly better than the polite approach of asserting my rights (and then shutting the fuck up) I use now. The polite approach tends to make them falsely believe I am a push over. The only real reason I use it now is because body cams are everywhere and I assume the judge will be watching exactly what I say if I ends up in court. Before body cams I assumed the cop would just make up the most horrid shit possible so there was not point in being nice.
Course it makes not much difference now. I'm on CBP's watch-list or some shit so I'm in for the 16+ hour shit-show, fraudulent warrants, with HSI detectives and the works everytime anyways. Even the seemingly nice agents see it on the computer and say "you know the drill" and send me into the bad-boy room.
Growing up in a family that came to this country, you're very disabused of the notion these agents have much power.
For most of them it's a power trip. Once you understand that, you will figure out what to say.
You have to understand that they know they're lying to you but it makes them feel powerful. Play into it. Let them feel the rush of power but remain firm in your goals.