Amendment the First:
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
It is interesting in how [they] are approaching the issue.
Constitution says, “Congrass shall make no law” but, in this instance (as in others) it is an agency of the Executive Branch that is making regulation outside of Law and then applying it as if it were Law.
So, in their minds, this is not unConstitutional, just extra-Constitutional and therefore...an issue for the SCOTUS to resolve.
While it is quite plain that the SCOTUS would strike this down, [they] get to carry on until someone brings suit.
Currently, there is no one in Congress (the body who can prove harm) with spine enough to do it.