Its OK to have a different opinion Tim. Thats why we are all here to discuss.
I'm surprised you are in favor of this though.
Occasionally, I'm asked my citizenship. But no proof required, to date. The dog usually takes a sniff around the car but I guess they see my big ugly white ass driving and wave me through. Seems pretty pointless. I suppose if I were hispanic looking there would be more questions. Maybe they are profiling the motorist passing through. TSA can't do that but maybe Border Patrol can. Its all DHS departments so I would think the government would have standardized rules.
And it damn sure IS arbitrary. The temporary checkpoints are set up/taken down/moved quite often. The dots on the maps I showed are the permanent checkpoints, the tent looking ones are temporary.