The key to understanding the Civil War, which began 150 years ago this week, is to realize that it’s still being fought. Indeed, it’s being fought now more intensely than at any time since the 1960s.

Then, African Americans and white Northern liberals and moderates battled Southern white segregationists and Goldwater conservatives to establish equal racial access to the ballot, housing and public facilities. Today’s battle more closely resembles the one that inaugurated the Civil War, which centered on the expansion of slavery to the lands west of the Mississippi. As in 1861, we are again divided over whether Southern or Northern labor systems, and Southern or Northern versions of government, shall become the national norm.

In the private-sector economy, the Southern labor system — in which workers are paid less and have fewer rights — has been winning for decades. Despite their huge growth in members during the 1930s and 1940s, unions never succeeded in penetrating the South, where white racial animosity toward blacks thwarted efforts to build working-class solidarity. The gap between Northern and Southern wages remained vast — so vast that many Northern companies began relocating facilities there, particularly after the civil rights revolution of the ’60s made the South seem less culturally foreign.

With the arrival of Wal-Mart in 1962 and the company’s expansion into America’s leading private-sector employer, the Southern labor system came north. Ferociously anti-union, and bitterly opposed to President John F. Kennedy’s decision to extend the minimum wage to cover retail workers, Wal-Mart developed a business model — documented by historian Nelson Lichtenstein, among others — that was premised on low-wage workers being economically compelled to shop at the lowest-priced chain — which, not coincidentally, was Wal-Mart. As Wal-Mart grew, it used its market power to compel manufacturers and companies along its supply chain to lower their wages. When Americans could no longer be found to make products as cheaply as Wal-Mart wished, the chain turned to China, where labor was cheap and workers had no rights. Not slaves, to be sure, but not really free, either.

In the United States, everyday low wages and the diminution of worker rights spread north, abetted not just by Wal-Mart’s growth but also by the growing mobility of capital and the Southern domination of the Republican Party. With Ronald Reagan’s election as president, the Republican right, centered in the white South, took control of the GOP and hostility toward unions became the norm for American business. The incomes of American workers, which previously had risen as the economy grew, began to flat-line. Low-wage jobs abounded; mid-wage jobs decreased. Nationally, the South’s low-wage, no-union labor system has prevailed, though in many Northern and Western cities that remain bastions of liberalism, governments have enacted living-wage ordinances and blocked the entry of Wal-Mart into their markets.

In the public sector, the battle between Republicans’ radical anti-government agenda and the Democrats’ (semi-hemi-demi, alas) defense of government’s role in nation-building is just the latest version of the sectional conflict that has divided America since the early 19th century, when Northern Whigs such as Abraham Lincoln favored government investment in canals, roads and rails against the opposition of Southern agrarians. Today, under Republican budget constraints, the traditional Southern underinvestment in infrastructure and education threatens to become the national norm.

The division between Republicans and Democrats over government’s proper role has been deepened by the re-sectionalization and heightened racialization of American politics. In the Deep South today, there are almost no white elected Democrats (just one white Democratic U.S. representative in all of Louisiana, Mississippi, Alabama, Georgia and South Carolina).

Moreover, as the share of Americans who are white continues to shrink, Republicans are doubling down on identity politics. In Texas, Wisconsin and other states controlled by Republicans, legislation designed to diminish minority participation in elections is advancing. Republican lawmakers’ almost-universal opposition to the Dream Act, which would grant citizenship to the children of undocumented immigrants who have served in our military or gone to college, displays a refusal to acknowledge the humanity of minority youths that would have done a segregationist proud.

With its paranoid misreading of Obama as a socialist (echoing the 1860 South’s misreading of Lincoln as an abolitionist), with its zeal for confrontation and its utter disregard, evident in its 2012 budget proposal, for the minority poor, today’s Republican right betrays a mind-set that hearkens back to the secessionists who fired on Fort Sumter. Shutting down the government isn’t comparable to shooting it down, of course, but the South’s war on egalitarian government and labor standards threatens again to diminish our country.