Well all the “changes” they harp about were constitutionally passed. So they are legal and “Constitutional”. Whether they should have been introduced and passed is a different discussion. The Constitution doesn’t prevent us from being stupid & careless - passing stupid poorly and/or thought out amendments can be done ! And we have done it!
I would argue we are on our 4th or 5th “Republic”.
1. Articles of Confederation - 1st Republic,
2. US Constitution - Date Effective 03/04/1789 - 2nd Republic,
3. Post-Civil War US Constitution - 3rd Republic For better or worse changed balance between states & fedeal government,
4. Ratiification of the 16th Amendment US Constitution - 4th Republic Created huge imbalance in funding between the states & the federal government. He who has the gold makes the rules. Fed has the gold they make the rules.,
5. Ratiification of the 17th Amendment US Constitution - 5th Republic Turned the states effectively into provinces. Made us more a democracy then a Republic as the Founders intended. We are now seeing all the consequqnces that too much democracy (mob rule) brings. The Founders warned us !
And no I am not necessarily implying that the earlier Republic iterations were perfect, error free or even necessarily better. There were necessary changes, but the consequences to those changes were at times managed poorly and often violated the republican (little “r”) spirit of the US Constitution
The “theorists” have an explanation that the passage of the 14th amendment was invalid. Like I said, better left unsaid.
Your thumbnail analysis of four or five “republics” seems, at least on the surface, worth pursuing. Good take.
Mischievous suggestion for a sixth republic - the 19th amendment. ;-)