[kabar]

In that regard, I fully expect the anti-MAGA Biden/Obama Admin (bent on "remaking America") will attempt to bestow with his final act a preemptive pardon on all who may be in the U.S. on his last day in office.

Unconstitutional. He doesn't have the power any more than he has the power to make DACA recipients citizens. He would be dealing with an entire class of people, which is not possible under existing immigration law. Congress would have to do it in the form of a law. Reagan's 1986 amnesty was the result of a law passed by Congress and signed by the President.

Does the pardon power apply to non-citizen, illegal aliens? Doubt it.

[frog in a pot]

Unconstitutional. He doesn't have the power...
That seems a difficult argument. He clearly has the authority to grant a preemptive pardon for crimes yet to be committed.

Does the pardon power apply to non-citizen, illegal aliens? Doubt it.
Noncitizens clearly have U.S. Constitutional protections. Do you think this Admin would hesitate to face a challenge on that issue?