The most talked-about article in Washington this week is the one by political scientists Thomas Mann and Norman Ornstein blaming political polarization and gridlock on the Republican Party. They say that its breech of longstanding norms of political competition, especially routine use of the filibuster in the Senate, has gone over the line. Mann and Ornstein blame the extreme rightward tilt of the GOP for its destructive behavior.

The political scientist Jonathan Bernstein agrees that the Republicans have moved well to the right and have become more radical in pursuit of their agenda. But he argues that these are two different phenomena that are not necessarily related. Bernstein thinks the GOP has simply become dysfunctional. He points to the purging of conservatives such as Senators Robert Bennett of Utah and Richard Lugar of Indiana merely for being insufficiently aggressive in attacking Democrats.

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The roots of political polarization go back to before the Civil War. The slaveholding society of the old South necessarily imposed upon it a very conservative view of the world, which impacts public policy to the present day.

One way in which this conservatism exhibited itself and still does is that Southerners tend to be very religious in an evangelical Christian way. The reason for this is that when slavery came under attack by Northern abolitionists, Southerners found comfort in the Bible. In it there are many passages that defend slavery and treat it as a normal part of life (e.g., Exodus 20: 20-21; Ephesians 6:5; Colossians 3: 22).

Perhaps the clearest biblical defense of slavery is that in 1 Timothy 6: 1: “Let all who are under the yoke of slavery regard their masters as worthy of all honor, so that the name of God and the teaching may not be defamed.”

A complement to biblical literalism was constitutional literalism. Southerners noted, correctly, that the Founding Fathers did not ban slavery and, indeed, accepted it as a necessary condition of the great compromise that led to creation of the United States. Several provisions of the Constitution implicitly defended slavery as an institution, and the concept of states’ rights severely limited the federal government’s ability to do anything about it.

The Southern states also adopted extremely conservative tax and spending policies due to slavery. Since much of the wealth of the South was in the form of slaves, slave owners were always concerned that they might be made to bear a heavier tax burden as a consequence. The limitation on direct taxes in the Constitution was primarily to shield slaves from federal taxation.

In the “Jim Crow” era after the Civil War, Southerners resisted efforts to improve public education because they believed that African Americans would be the primary beneficiaries.

In the “Jim Crow” era after the Civil War, Southerners resisted efforts to improve public education because they believed that African Americans would be the primary beneficiaries. They also resisted spending for better transportation because convict labor was a very cheap way of maintaining roads that justified harsh penalties for law breaking, especially by black males, who were often sentenced to long prison terms by kangaroo courts just to provide quasi-slave labor for the state.

And of course the “Bourbons” of Southern society wanted taxes kept low to maintain their wealth and lifestyle. It didn’t bother them if the public schools were dreadful because their children went to private academies.

The point is that political, economic and cultural conservatism has deep, deep roots in Southern society. Under normal circumstances, Southerners would naturally have gravitated toward the more conservative of our two major political parties, which has long been the Republican Party. But because it was the party of Abraham Lincoln and abolitionism, Southerners remained strongly averse to the GOP for more than 100 years after the war.

Consequently, the most conservative region of the country remained solidly Democratic, an anomaly within what has long been the more liberal party. This marriage of convenience gave the Democrats control of Congress almost continuously from 1932 to 1994. It also long protected the South from legislative efforts to stop lynching, integrate schools, and provide voting rights for African Americans.

The liberalism of the New Deal, however, began pushing Southern Democrats closer to the Republicans, especially on economic and national security issues. Franklin D. Roosevelt’s efforts to pack the Supreme Court and purge conservative Southern Democrats in 1938 pushed them into an alliance with Republicans that effectively controlled Congress throughout the 1940s and 1950s.

The real death knell of the conservative Southern Democrat was Watergate, which led to a vast influx of liberal Democrats into Congress beginning in 1974.

This was the golden era of bipartisanship, as shown graphically in the work of political scientist Keith Poole. Southern Democrats organized Congress with liberal Northern Democrats and were rewarded with committee chairmanships and other leadership positions, which they used to prevent the federal government from doing anything to undermine segregation.

But beginning with the Brown decision in 1954, federal courts began forcing the race issue onto the national agenda. The civil rights movement pressed Congress and eventually it acted with the Civil Rights Act of 1964 and the Voting Rights Act of 1965. But the real death knell of the conservative Southern Democrat was Watergate, which led to a vast influx of liberal Democrats into Congress beginning in 1974. They made no secret of their disdain for their southern brethren and they were actively pushed out of the party in various ways. For example, a number of Southerners were ousted from their committee chairmanships.

The alienation of Southern Democrats from the national party provided the opportunity for Republicans to finally make inroads in the South. By 1994, the last truly conservative Democrats were gone and all either formally or effectively became Republicans.

The demise of the conservative Southern Democrat is the primary reason for the rise of political polarization. The era in which they held significant power in the Democratic Party was a historical anomaly; polarization is actually the norm, to which we are now returning. The good old days of bipartisanship are as dead as the conservative Southern Democrat.