[Wonder Warthog]

"Even Amendments must be compatible with the principles of the Constitution."

Wrong. Amendments can change any aspect of the Constitution. There are no limitations on the amendment process.

"Marshall said as much in M v M, -- that any law 'repugnant', - is null & void."

A Constitutional Amendment is not a "law". It is a completely different animal.

"Theoretically, the SCOTUS could 'strike down' an Amendment as unconstitutional. -- And that exact point was argued before them in 1919, in a move to nullify the 18th."

Nope, 'fraid not. Amendments trump the SCOTUS, hands down.

[nicollo]

re. amendments

Actually, ammendments can and do conflict. A simple example is the 21st, which was used to trump 1st amendment protections of speech regarding advertising of liquor. (The courts went both ways on that one, ultimately upholding the 1st amendment.) On a more fundamental level, the 14th poses a good number of problems to the 9th and the 10th.

[musanon]

Even Amendments must be compatible with the principles of the Constitution. -- Marshall said as much in M v M, -- that any law 'repugnant', - is null & void.

A Constitutional Amendment is not a "law". It is a completely different animal.

The Constitution and its Amendments are the "Law of the Land". -- See Article VI.