If illegal immigrants were possible to be identified easily by the IRS, ICE would have taken them over already.

The problem is two-fold. A lot of the immigrants who fall into this “illegal” category are not on the books, they get a brown envelope, and pay little to no taxes at all. And the more “sophisticated” ones look just like your average American. So if you taxed them more, you’d be affecting a lot of the “legal” population as well.

Also, the American economy is full of jobs that no “non-deportable” would like to do. Agricultural jobs come to mind. The current regime’s idea of eradicating all illegal immigrants runs contrary to a lot of economic interests (and I read that they’ve done a lot less deporting on the farms recently. Curious …) Even if you could just tax them more, you’d still mess with those interests as well.

And while I’m not a tax lawyer, I’m gonna go out in a limb here and say it’s not going to be easy to make a tax law like that that isn’t going to be heavily scrutinized in the courts because it is unabashedly discriminatory.