With due respect, that problem is on CBP. I am somewhat (albeit decreasingly) sympathetic to the unique challenges that immigration enforcement agencies face in the US. We live in a country where the citizens have decided democratically that no US citizen will ever have to carry proof of US citizenship, and moreover, that national ID and standardized proof-of-citizenship passports should not even be mandatory for citizens to possess, let alone carry. We even decided that the Federal Government should be explicitly banned from creating those forms of ID.

We made these decisions for various reasons, but broadly because the voters felt that US citizenship and lawfullness should be presumptions, rather than something you had to prove in order to enjoy your rights as a citizen.

For an immigration agent, this is really tough. You have to identify unauthorized immigrants in an environment where you can't just require lawful citizens to carry ID or proof of citizenship. You legally can't arrest or (more than briefly) detain a US citizen for failure to carry citizenship documents. You have to walk on eggshells even with actual unauthorized immigrants, to avoid violating the law. And our proof-of-identity document systems are deliberately decentralized and unreliable, so you can't just check a master database. It's a tough problem!

But that's the way the cookie crumbles. We designed our society to make this kind of "papers please" enforcement difficult, which means that immigration enforcement needs to be smarter and more savvy, or else we need to actually change the laws. What ICE and CBP are trying to do now is just to ignore the law, and that doesn't work. Citizens' built this law to protect their rights; you can't just take away those rights because CBP have a tough job.