A minor point: It's not in the Constitution.
Another minor point : Even if/when any person can prove the process was not followed correctly, the lawyers in government (including judges) simply rule that it was intended. If someone proved beyond doubt that the income tax of today is unconstitutional and illegal, I have no doubt that the courts would nonetheless order its enforcement "because of national security". This applies as well to any that would cause loss of bereaucratic authority . Those that gain power NEVER willingly give it up.