We've come a long way, baby.
The nytimes this morning has an article about the Secession movement in Texas.
This phenomenon and the seeming ideological schism between Americans these days is reminiscent of the late 1850's descent into war between States. Superficially, at least, and I would argue that is all it is: posturing by powerless people, and that it well illustrates how very much the War changed things.
In 1859-60 a powerful special-interest group of citizens (big land and slave owners) and politicians quasi-illegally seized control of legislatures in the various southern States and were able to make those States secede. It was a coup, by any definition. The little people, for the most part, were against it. Afterward, events took control.
Switch to now: a diffuse group of disgruntled citizens (with little or no power) and minor politicians have by-passed State political machinery and are pressing the Federal government directly to allow secession of a State. All actual power in that State is opposed to the idea (in part because they are probably a bit better educated about history), so Obama will simply issue some kind of platitudinal formal opinion on the matter and that will be the end of it. Much like Occupy Wall Street, it is toothless and can be easily and safely ignored or patronized a little for brownie points.
So that is the "state" of things and much has changed. Nobody will be mounting their steeds for Texas to teach those rebs a lesson, because the lesson was learned: work the system, don't fight it.