In the months before the April 12, 1861, firing on Fort Sumter, there were lots of sharp divisions in the North about the proper reaction to the first seven Confederate states that had already left the Union.

Not all Unionists believed a civil war was inevitable: Some, in fact, were happy to be done with the departing South and thus see the stain of slavery gone from the Union.

Similarly, others agreed that the emerging Confederacy was not worth the trouble and costs of war, and the secessionists could just form their own nation and stew in their own backward, servile juice.

But after Fort Sumter, President Abraham Lincoln — who was hated as much by the Confederates as President Trump is by the woke and socialist left — gained a consensus that the Constitution had no clauses about any lawful departure from the Union.

It operated under a clear supremacy clause that made state obstruction of federal law and occupation of federal property veritable sedition.

Lincoln and the preservationists felt they easily had the moral high ground of abolition versus the continuance of slavery.

Nor did they want a North America of fragmenting, warring nations in the manner of Europe.

Something similar is emerging over Minnesota, the South Carolina of our age.

Once sanctuary states, cities and counties had established the precedent that, with impunity, they could nullify federal immigration law, what followed was a logical and growing descent into the current open defiance of the federal government.

How odd that self-described progressives are now acting out the visions of prior kindred nullificationists and neo-Confederates, from John C. Calhoun to George Wallace.

The reaction of the rest of the nation, especially its conservative half, to Minnesota resembles the 1861 disconnect in the North over the insurrectionary states.

Some believe that if Minnesota wants to protect its approximately 1,300 jailed illegal alien murderers, rapists and assorted felons, so be it — and ICE should leave such a dysfunctional and dystopian state to its own self-destructive path.

In this way of “See ya, wouldn’t wanna be ya” thinking, Trump should stick to the red and purple states and clear them of criminal aliens with the help of local enforcement — without interference from the organized performance-art leftist resistance.

Then he could show the nation the difference between low-crime, noncontroversial deportations, versus the blue-state model of protecting illegal-alien criminals indifferent to the mayhem they inflict on the innocent.

If Minnesota further wants to be a state like 1861 South Carolina that openly defies the federal government, then also so be it.

But it should accordingly not expect federal funding for its pick-and-choose approach to federal law and property.

On the other hand, contemporary Unionists object that such a live-and-let-suffer attitude is defeatist.

Moreover, millions of Americans inside insurrectionary Minnesota do not support their neo-Confederate leaders.

They properly see themselves as Americans first and Minnesotans second.

In this line of argument, just as Lincoln refused to give up federal armories, property and offices inside the South to insurrectionists, so too Trump has an obligation to protect federal property and offices in Minnesota and to enforce federal law throughout the nation.

Very soon, Trump will have to decide which strategy is preferable and politically viable before the midterms.

Meanwhile, Minnesota elected officials like Gov. Tim Walz, Minneapolis Mayor Jacob Frey and Attorney General Keith Ellison are actively encouraging Minnesotans to obstruct federal officers from enforcing federal laws — despite the mounting violence that follows their collective prompts.

For them, screaming for ICE “to get the f–k out of Minnesota” is more than mere braggadocio.

It is a reminder that the Democratic Party wants a safe place for illegal immigration, the fuel of a future dependent constituency — as the architecture of the recent massive Somali frauds attests.

They also believe that the more turmoil, the more violence, the more resistance and the more a general sense of chaos and unrest swirl around Trump, the more they can drive down his popularity before the midterms.

And the American public?

Polls reveal its trademark ambiguity.

A majority voted for Trump to enforce immigration law, close the border, end illegal immigration and deport those who broke federal law.

But that hope and the reality of implementing it are two different things — especially when a state like Minnesota has not just institutionalized illegal immigration but nearly canonized foreign nationals illegally residing in the United States.

For now, Walz, Frey and Ellison are upping the rhetoric, fanning the violence and talking openly about how best to nullify federal law and impede federal enforcement.

They are convinced that they have galvanized national opposition to the hated Trump, smothered the Somali fraud scandal and stopped ICE deportations of their constituents.

In all of those assumptions, they have little idea they are following the Confederate script to the letter.

And like their spiritual forefathers of 1861, they grow ever more cocky, boastful and defiant as they create martyrs, spread narratives of victimhood and daily slouch toward another Fort Sumter.

Victor Davis Hanson is a distinguished fellow of the Center for American Greatness.