Actually, when it comes to secession, it is up to the Feds only until they no longer challenge a state.
If a state declares independence, no US court can legally compel them to follow its orders, or, any US Federal law. The Feds can only enforce the law if they choose to go to war.
Unlike the Civil War, the Feds do not have certain advantages now that they enjoyed in 1861-1865. States have much better infrastructure and communications networks now than the Confederacy did in 1860’s. Also, since so much of our manufactured products are now made overseas....the Feds would have a much harder go getting materiel for war...and some of the basic things would require foreign nations to supply...even the most blithering Globalist apologist knows that this would be a great opportunity for Communist China to slap down a US federal government in war with seceeding states.
Secession attempts would be fun for China even if the US didn't resist them. In fact, you could probably look forward to China supporting such movements.
Unlike the Civil War, the Feds do not have certain advantages now that they enjoyed in 1861-1865. States have much better infrastructure and communications networks now than the Confederacy did in 1860’s.
No state is ever likely to be as unified about anything as the cotton-belt states were about slavery in 1860.
Secession now would mean a true "civil war" (if the last one some how wasn't): fighting in the streets of Atlanta or Dallas, Charlotte or Houston.
Maybe brother against brother and neighbor against neighbor, but certainly one side of town against the other.
Enjoy.