Virtually every word of your post indicates that you do NOT know how the Constitution was created nor what it actually means.
Legislatures were DELIBERATELY kept out of the ratification process because the intent was to keep them from using the argument you use. A constitution is not an ordinary law which can be changed by legislative action. The founders made sure that was the case.
State legislatures in NO way approved entry into the Union. Their ONLY role was to establish CONVENTIONS within the states to decide the issue.
The “feds” sparked nothing. Lincoln had to defend US institutions and property ATTACKED by the slavers.
Horseshit. I used the terms I used colloquially, rather than waste bandwidth explaining the process. You jump on this like the damned spelling Nazis. Who are the Legislators? Who are the convention attendees? Where did they come from? Are you remotely familiar with the history of the United States between 1840 and 1861? To say that the Feds did nothing to spark the war is ignorant in the extreme. You really need to do some research.