Yes Yes and Yes
Legal ... The IRS has to implement the taxation once the law is codified
Constitutional ... Congress has to pass the tax law that requires the tax and authorizes the IRS to do so
Pragmatic ... None whatsoever
However .............
Congress will never do it, because they want open borders and unlimited immigration for their donors, the Chamber of Commerce, Big Business and down the road, the Dem’s want the voters. Throw on top of that, Western Union, et al, have some deep pockets and good lobbyists that have and will fight this and when no one is looking, pass the envelope full of cash to the appropriate Congressperson or have them on video doing stuff they aren’t supposed to be doing.
And all the while, you, me and everyone else gets left paying the bills.
And getting the diseases, watching our neighborhoods turn into toilets, being forced to ramp up security measures against the criminals who manage to slip the system, etc. Lord I hate those people (the ones who foist this onto us while they live apart and above it).