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While some bemoan Punch and Judy politics the real issue tearing apart the country aren’t the stark ideological differences between Democrats and Republicans, conservatives and liberals, but rather the divide between those who want enforcement of federal immigration law and those who defy and obstruct the enforcers.

This is an issue — and a debate — that has been percolating for years, though it arguably only came into full focus with President Donald J. Trump’s signature campaign promise to “build the wall.” In time, building a wall along the border of the United States and Mexico became a euphemism for enforcement of federal immigration law, including a crackdown on so-called sanctuary cities.

As with much in this debate, sanctuary cities are nothing new.

The usual left-wing bastions became safe spaces for illegal immigrants years ago. However, cities and counties that prohibit local police from some or all cooperation with federal authorities charged with enforcing immigration laws gained new infamy after 32-year-old Kate Steinle was murdered along San Francisco’s famed Embarcadero waterfront by Jose Ines Garcia Zarat, a Mexican illegal immigrant who had been deported five times from the United States and had seven felony convictions to his name.

Just as Arizona tried to enforce federal immigration law during the presidency of Barack Obama, California has gone in the opposite direction and become a sanctuary state.

At stake isn’t just the potential loss of federal money, which in the case of California, the most populous state, is significant. California, where reportedly 10 percent of the workforce is in the United States illegally, didn’t just increase the stakes. It poured fuel on the fire with its open defiance of the feds.

As a result, a dangerous and divisive atmosphere not seen since the Civil War is engulfing America.

Then as now, the differences between the two sides are seemingly irreconcilable. And ironically enough, the battle lines are the same with Democrats once again taking what amounts to the secessionist position.

In Oakland, San Francisco’s neighbor across the bay, the Democrat mayor, Libby Schaaf, used the full weight of city hall to warn her constituents about impending raids a day before U.S. Immigration and Customs Enforcement made 150 arrests.

Meanwhile, California Attorney General Xavier Becerra threatened state prosecution of businesses that disclose the legal status of their workers to federal authorities. This despite the fact that Becerra, a Democrat, swore an oath to “support and defend” and “bear true faith and allegiance” to the U.S. Constitution.

Under these circumstances it isn’t far-fetched to imagine a situation in which a sheriff or police chief, encouraged by the political leaders of a sanctuary city or state, physically hinders the feds from carrying out a raid in their locale.

Not only would this escalate the issue, but also it could turn what has been a heated political debate into civil unrest and even, dare I say, insurrection.

California’s deliberate undermining of the legitimate and lawful exercise of the federal government’s authority is beyond unconstitutional. It presents a danger for the Union.

Dennis Lennox is a political commentator and public affairs consultant. Follow @dennislennox on Twitter.