I can't comment on the bounds of acceptable scholarship, but I don't know that the facts support the position. Others may disagree, but this is how I see it:

The theory of states' rights, as usually advanced, was something like the idea that every state should have the sovereign right to decide its domestic institutions as it saw fit. That right could never be sovereign if the federal government had the authority to intervene and overrule such state determinations. There are many different interpretations of how far that should go and what remedies a state could have if its sovereignty was abridged, as well as at what point new states acquired that sovereignty, but I think that fairly states the central idea.

People in the past, like people today, said a lot of things. Words are cheap. Actions cost us more dearly. People disagree over how to weigh the two in comparison, but I think it's fair to look at both but weigh the latter more heavily.

If slavery was an example of states' rights, then the men who advocated for its protection believed in the antithesis of states' rights. They spent the decade before the war inventing more and more extreme ways to safeguard slavery at the expense of local autonomy on every front. This included, in Virginia's case, actively pursuing a lawsuit (Lemmon vs. New York) that had at least the potential to render the notion of a free state legally impossible, just as Dred Scott v. Sandford had rendered free territories legally impossible. The two cases were eerily similar, both dealing with slaves brought into a free jurisdiction apparently freed by its laws. Both directly challenged the legitimacy of the laws under which the emancipation occurred. In the Lemmon case, Virginia argued that New York's law prohibiting the import of slaves violated the Commerce Clause. This at least implied that had the Supreme Court sided with Virginia, it would be legal thereafter for people to go into New York and any other "free" state and go so far as setting up an actual slave market and holding auctions. But Virginia saw opportunity to try the issue on the battlefield rather than in the courts and proceeded to do so.

The same pattern plays itself out in the case of the Fugitive Slave Act of 1850. In the 1842, Prigg v. Pennsylvania's held that slaveholders pursuing slaves who stole their bodies from their lawful owners had the right to cross state lines to recover their human property. That's right in the fugitive slave clause of the Constitution. But Prigg also held that states did not have to help the slaveholder do so. This resulted in a flurry of personal liberty laws which granted accused runaways various rights to challenge their rendition. Practically, this was a decisive states' rights decision and the states exercised their sovereignty through those grants to runaways, provisions barring the use of state jails and the involvement of state officials in renditions, etc. That exercise of sovereignty so exercised the allegedly states rights southerners that as part of the Compromise of 1850 they secured the aforementioned law to override it. Not only did the Fugitive Slave Act overrule state laws, it went a step further and essentially set up an ersatz draft of any and all northerners into impromptu slave catching bands. You could be deputized on the spot as a person ran past you and required to aid in his or her capture, under penalty of severe fines. The law also made concealing and aiding fugitives a federal offense.

Plenty of white northerners didn't like that, in principle, but could live with it. Some, however, would not. They risked the penalties and went so far as to rescue fugitive slaves by mob violence, most famously from Boston where the failed rescue of Anthony Burns resulted the death of a deputy US Marshal. Burns' case is actually late in the game so far as resisting the Fugitive Slave Act goes, but his rendition involved a great expense and calling up the army and Massachusetts militia to maintain order while he was marched out to a revenue cutter and taken back into slavery. Before his 1854 rescue, other cases in Boston and down in Pennsylvania had provoked southern accusations of treason on the part of the resistance. One would not expect this behavior of people who believed in the right of local authorities to resist federal impositions, most especially not on the vital issue of what labor system a state should adopt...unless the only vital issue was that they adopt, or at least go out of their way to facilitate, slavery. Why, after all, should it be Massachusetts' or Pennsylvania's job, and the job of their citizens, to preserve the slavery of Virginia or Maryland?

Burns' case resulted, in part thanks to its timing with another issue I'll get to in a moment, in widespread resistance to the Fugitive Slave Act across the North. This effectively nullified it. Southerners did not forgive and forget and the North's failure to act as slave catchers on demand figured into the statements of grievances that the seceding states made in 1860-1.

At the same time as Anthony Burns' case came to national attention in Boston, Franklin Pierce was putting his name to the Kansas-Nebraska Act. This repealed the Missouri Compromise's ban on slavery in essentially all the land between the tier of states immediately west of the Mississippi and east to the Rockies, from the southern line of Missouri up to the Canadian border. For thirty years, that federal enactment had barred slavery from all the land save the territory of Missouri itself. That repeal sounds like a decision in favor of local autonomy. The man who initiated the repeal proposal, Kentucky's Archibald Dixon**, defended it on those grounds. Congress always made a mess of these things, so let the locals decide. States' rights men were happy and would even spot incipient states, in the form of just-organized territories like Kansas, the sovereignty to decide for or against slavery. Or so they said.

The Kansas locals might very well have decided for slavery. Most of them came lately from Missouri, after all. But Missouri's most enslaved area directly abutted the border and its slaveholders did not care for risking a safe haven for absconded slaves in their neighborhood. They came over and fraudulently voted in Kansas' elections in the thousands, in a territory that only had a few thousand legal voters. They came armed and well-lubricated, even toting along cannons, led by no less than just former Senator (and instrumental figure in getting the Kansas-Nebraska Act to its final, proslavery form) David Rice Atchison. They threatened violence against people who contested their "right" to vote illegally and proceeded to carry it out in several cases. In one district, they burst into the polling place and told the election workers that they must let everyone vote without question (The judges of election had the right to question voters under oath to ensure they were entitled to vote in Kansas.) and without swearing any oaths. They have five minutes to decide, but if they decided against complying, they were dead men.

The House sent out a committee to investigate this mess a year later and they ruled that from its inception, the government of Kansas had been dominated and controlled by Missourian proslavery men. This extended even to the point of their forcing local Kansan proslavery men to set aside their chosen proslavery candidates for office and vote for men chosen by the Missourians. Local autonomy? Not so much. They wanted a slave territory that would become and remain a slave state. With their control of the legislature, they set about doing it by criminalizing essentially any act of antislavery politics up to and including debating over whether or not slavery could or should exist within Kansas.

Kansas wasn't then a state, but it got states' rights. In fact, it was entitled to them right up to, and no further than, the right to have slavery, whether wanted or not, good and hard. I think it's a good microcosm for the whole issue. The violation of white male republicanism (many didn't care that much about the slaves in themselves, but about the threat slavery posed to their freedoms as white men) there certainly gave a lesson to white northerners elsewhere about just what a future in a Union half slave and half free might look like. That free half would exist on paper, maybe, but may soon no longer extend into any reality.

In 1860, the dispute that split the Democratic party and thus gave Abraham Lincoln the Presidency is a particularly telling one. Southern radicals insisted that the party platform, which actually meant something in those days, must include a call for a federal slave code to apply in the territories. The northern Democrats refused and the sides could not reconcile. If they really believed in local autonomy, then why did they insist upon imposing slavery upon future states and then demanding if they wanted it gone, they must vote it out after it had been established in their bounds?

I think that if one wants to parse things very finely, one could say that secession was the proximate cause of the Civil War. But the preservation of slavery was the cause of secession.

**NB: Stephen Douglas (D-IL) wrote the bill, but it saw tremendous revision by others to win southern support. Douglas went along with all that, but his original version kept the Missouri Compromise more or less intact.

Follow on question...

Would any states have seceded if the federal government forced unwanted, but non-slavery related laws upon them?

Might answers to this question help analyze which 'causes' were proximal and/or underlying?