Quick Con Law Question

Hi I have a quick question about con law don’t get this question.

Assume that Congress enacts a law the final section of which provides: “This law will not be repealed or amended except by a 60% or greater majority in both of Congress.” Is this final section constitutional? Explain why or why not.

Assuming that section was an otherwise sound expression of federal power, I do not see how it would be unconstitutional. However, it would be a nullity. That would not be binding. You would need a constitutional amendment for that.

I thought it would be unconstitutional because of the line item veto. President can veto a repealed law

The constitutional provision would take away that power violating the separation of powers

And moreover, it would require two-thirds majority of congress 66% rather than 60% for Congress to override the president’s veto

i could be way off though

bump. test is in an hour. hoping to see other responses