It might be they ask every 10th person or who knows. I am OK with them asking, I don't think it will hurt anything, it probably won't help anything either though. Sort of like this sticker they put up in my office - a gun with a red cross out through it. hmm. Sure we are safer now? I just think it's so if some nut job goes bonkers and they track where he bought the ammo then the store can say they tried.
If Trump were elected and they were to completely double down on finding undocumented folks then we'd all better get used to proving we are supposed to be here at every turn. Checkpoints everywhere, better hope our paperwork is in order. good times.