Ok, so you got me doing a little digging, and it appears that SCOTUS has not squarely decided the issue of secession legality.  In fact, it is argued that this is why Jefferson Davis was never tried for treason; the Union didn't want to have the courts to possibly recognize it as legal if Davis successfully argued that he wasn't a traitor because the Confederacy wasn't technically part of the U.S.  Now in Texas v. White (1869), SCOTUS did say that secession was not legal, but it sounds like this was more of an ancillary declaration which means it doesn't hold a lot of weight and that the issue is still unresolved.

But I think you're right that this would have to be a voluntary break-up through something like a constitutional convention.  That would be the most peaceful way of proceeding.

Think of it - if conservatives start playing the dirtiest of games the way the left is doing it, what would it accomplish?  Nothing but further division and fighting, AND depending on how dirty we fight, we might also become one of the "bad guys".  We'd then have to break up at the end anyway. 

So rather than postponing the inevitable, I say we retain our integrity, take our ball, and stop playing the game with the left.

I'm of the legal view that for a person to trigger incitement under Brandenburg v. Ohio, one's language really has to be closely and causally linked to the potential for violence.  We should really be conservative when nailing people for unlawful speech via incitement claims because of the First Amendment.  Striking down speech should not be a thing we just do casually.  The left overplayed its hand by claiming that Trump incited the riot in January, so I think that the right should hesitate to accuse Maxine Waters of incitement just yet.

With that said, wow.  Just wow.  Based on the Trump standard, perhaps she should be impeached for what she said.  For a member of Congress to demand a certain verdict is highly alarming, and to couch it in terms like she did, is very disturbing.