In the 1800s, sure, secession was worth the Union going to war over, but in modern 21st century American society, if one or many states attempt to secede - legally or illegally - would or should the federal government just slap some embargoes and sanctions on the seceding nation-states and let it be that?
I can’t see how the public support would be there for a military war against secession again.
Absolutely not. If the states of the old confederacy want to secede again, I say don’t let the door hit you in the ass on the way out. Imagine how progressive the US would be if it were rid of its southern dead weight.
Probably because outside of a few nutty secession movements there is no real support for a state or states leaving the Union, so the public doesn’t give it much thought. If there ever was then you’d see the public take an interest in the subject.
The thing is, if, say, Texas decided to leave the Union you’d have to consider what to do about the large percentage of Americans that didn’t want to leave the Union, at the very least. Assuming you could ever get enough people in Texas to agree it would be a good idea you’d still have a huge number of folks who don’t want to not be Americans anymore and to live in a new sovereign state outside of the Union. You’d also need to consider what would or wouldn’t be US assets in Texas and a host of other messy things.
So, I think that it’s unlikely in the extreme that even Texas would secede from the Union, but if it tried then opposing it through military force might or might not be ‘worth’ it, depending on how they went about doing it and whether all the mess could be resolved. If a minority of Texans (and I’m simply using Texas as an example since there is a small, nutty secessionist movement there) decided to seize control and secede then that should certainly be opposed through military force. If a super-majority of Texans decided to secede then, depending on how the details could be worked out that might not call for military force to reconcile a split of some type.
And if New England wants to go as they have at several points in our history imagine how conservative the rest of the country would be if we got rid of all of that liberal hot air! 
Of course, imagine how hard it would be on all of the folks who want to stay Americans who would have to move or live with not being able to do that anymore, and how messy and disruptive it would all be. But, hell, don’t let reality get in the way of a good rant, Bob, or the fantasy of just cutting loose all of those state you personally dislike, amirightorwhat??
Was secession worth fighting with force in the 1860s? If so, why wouldn’t it be worth fighting in the 2000s?
True, but even if there were real support for secession, I don’t think most Americans would have the stomach for a violent civil war against Texas or some other state. I think public attitudes are simply far different and “live and let live” now.
I don’t think we want to decide this based on political bias. It’s OK if conservative states secede, but NOT OK if liberal states decide to do so? Or, would you be OK if, say New York, instead of Texas was the seceding entity? Because your argument certainly implies you wouldn’t. Perhaps you could explain further…?
But I think XT hit it on the head: Depends on the specific circumstances.
What if it was the West Coast (California, Oregon, Washington) seceding?
What’s missing from your discussion is the fact that the US does not exist in a vacuum. We would have international players to consider. History teaches us that when there is a dispute in a country, other countries want to step in an pick sides, offer support, arms, troops, etc. - in order to fight proxy wars against their perceived opponents.
If say Texas really tried to succeed, they would likely need to align with a sponsor. Who would that be? Russia? China? Mexico?
In a case like that then the rest of the US would have no problem wanting to send in troops.
Depending on the state, you’d get people wondering if it was too late to clone Sherman.
I disagree that the public’s attitude would be ‘live and let live’ depending on the circumstances. I think that if there was a super-majority of citizens in a state that wanted to leave the Union, and if the details could be worked out peacefully then you might have this, but I can see several scenarios where Americans would be in favor of using force against a state trying to leave the Union by fiat or in other ways. Trying to predict when Americans will or won’t have ‘the stomach’ for war or fighting is a fools errand, since it changes with circumstance and public opinion and isn’t a set in stone kind of thing.
I would hope that they didn’t because it would effectively turn the rest of the states into Jesusland. Without those reliable blue votes, Democrats might was well pack it in.
I base my support or opposition on what would remain after secession. Would it be a progressive bastion of minority rights, women’s rights, gay rights or would it turn into a right wing anti-labor hellhole?
In the 1860s the nation was young enough that secession would very likely have resulted in the breakup of the entire nation had it been allowed to happen. I don’t that is the case today.
Are you talking morally, or legally?
Legally, if a country has the right of secession built into its constitution (like the old Yugoslavia did) then yes, constituent regions have the right to secede, and the central government was wrong to stop them. I don’t think the United States in 1860 had any such comparable right.
Morally, it depends entirely on whether the political order that the new state wants to establish is better or worse than the old one. Texas seceding from the US (or Mexico) to maintain the institution of slavery is a bad thing (in my book). South Sudan seceding from the north because they don’t want to live in an Islamic theocracy is a good thing (again, in my book). Your opinion about the morality here is of course going to depend on your premises.
So you’d support a secession that led to the new nation being a “hellhole”?
As a resident of one of the old confederacy states, this is ridiculous. Even if the majority of the south wanted to secede again, that doesn’t mean they should get the right to dictate to southerners who don’t want to secede what country they will be in.
So, you’d throw tens of millions of fellow citizens into that hell-hole just to make it easier on some smaller nation with less influence to have the correct ideology? That is a really selfish view, and borderline monstrous. You’re talking about letting letting huge swaths of people this country has a resonsibility to have their citizenship revoked (which the Supreme Court has foudn to be a cruel and unusual punishment) and then letting whatever harms the majority of the new nation inflict upon them go without their elected officials and government agencies (which these people have paid tzes their whole loves to support) so much as raising a finger to help protect them. It’s beyond insane, and completely immoral.
What if its America at large that is going down the hellhole and it is the state that is trying to leave the sinking ship so to speak?
How do you decide which is which?
The problem with this hypothetical is that you need to define why a state wants the secede before you can accurately gauge the interest of the rest of the nation in stopping them. There’s no issue that’s so divisive that anyone’s really talking about secession seriously. If there were an issue that people felt so strongly about that they wanted to leave the Union, opinions on the opposite side would likely be just as strong, making them more likely to try to stop the secessionists.
My opinion would be you don’t, you fix the ship.
So, you don’t care if it’s legal or not, you just want what you want. Sheesh, and you tell us the Republican’s ideas are dangerous!!