[BlatherNaut]

If the Constitution had a clause saying that Congress can pass immigration laws that the president can on personal whim enforce or not enforce, and that states are powerless to address

Separate issue.

Impeachment is the remedy when presidents deliberately violate the Constitution.

[xzins]

It was part of Scalia’s argument in dissent on the soveignty of states, so he wasn’t concerned with impeachment but in establishing that the power to decide who can or can’t enter your territory is the primary definition of sovereignty.