01/18/2011 02:20 pm ET Updated May 25, 2011

Partisans Like Us: How History Polarized Our Politics

In a recent New York Times column, Paul Krugman puts forth the basic thesis that the partisan divide in American politics is based on fundamental moral differences between left and right, and that the best we can hope for is to keep the debate over these divergent morals within the bounds of civility and non-violence. While I agree with Mr. Krugman that disagreement itself is not the problem, but rather the way in which we express our dissent, I was bothered by his reliance on what has become the political left's go-to explanation for the perceived increase in Washington's partisan polarization over the past few decades.

This deep divide in American political morality -- for that's what it amounts to -- is a relatively recent development. Commentators who pine for the days of civility and bipartisanship are, whether they realize it or not, pining for the days when the Republican Party accepted the legitimacy of the welfare state, and was even willing to contemplate expanding it. As many analysts have noted, the Obama health reform -- whose passage was met with vandalism and death threats against members of Congress -- was modeled on Republican plans from the 1990s.

Democrats, including Krugman, tend to push an argument that goes something like this. "Republicans used to agree with us on more issues. They don't agree with us anymore. Why won't they be bipartisan? It must be their fault." While it's true that the ideological rift between both sides of the aisle has indeed grown, Krugman's opinion as to the reason for this split makes the classic mistake of assuming that history follows politics and not the other way around.

Let's begin our trip through history and politics in the 1950s, the golden era in which Democrats want to work and Republicans want to live. The nation immediately post-WWII was about as homogeneous as it has ever been. Domestically there were large swaths of both parties which supported segregation and foreign policy was dominated for everyone by an overarching fear of the Soviet Union. Political disagreement between left and right still existed of course, but it's easy to see why this post-war era of massive economic expansion and the heyday of traditional Americana produced such mythical political creatures as southern Democrats and New England Republicans. Cultural unity, at least among those lucky enough to have the right to vote, leads to political unity.

This national ideological homogeny changed drastically in the 1960s, causing both Democrats and Republicans to make decisions which we would find utterly uncharacteristic of either party's platform today. LBJ, the same liberal Democratic President responsible for historic progress on Civil Rights and expansive "Great Society" social programs, escalated the war in Vietnam in the face of a growing credibility gap with the American people. Richard Nixon, a full-on Communist-hating Republican, signed into law the most expansive suite of environmental regulations in American history with the National Environmental Policy, Clean Air and Clean Water Acts. Perhaps the most profound political shift to come out of the 60s, and the one pertaining most to our current polarized political environment, is the split caused within the Vietnam generation by differing beliefs on duty, patriotism and political dissent. Some would argue the divide between those who went to Vietnam and those who didn't -- think Bill Clinton and John McCain -- is the defining and underlying source of differing political ideology between left and right to this day.

The changes didn't stop with the Summer of Love and the end of Vietnam, however. The late 70s and early-80s saw a fundamental shift in the national economic policy debate from what had essentially been different shades of Keynesianism among both parties to the rise of monetarist and supply-side economists skeptical of the government's ability to successfully fine tune the economy. Finally, the late-80s and 90s saw the rise of political talk radio and the Internet, rewarding those who could express political dissent through catchy, simple and hard-hitting rhetoric.

The politics of the past 50 years have become more polarized as we as a nation have become more diverse and adept at expressing ourselves. Our politicians and their opinions are only reflective of our cultural history. Those who bemoan the deepening partisan divide, or in Krugman's case use it as a petty political shot at the other side, seem content to ignore the fact that our political system is defined by the very voters it serves. If the ideological debate, as Krugman suggests, is indeed based completely in moral differences, then these definitions of good and bad must to some extent be based in cultural historical experiences. No one will deny, especially after the tragedy in Tucson, the need to keep our disagreements within bounds. To suggest, however, that one party, certain politicians, or the political class as a whole is responsible for the political environment in which we find ourselves is to have very little faith in power of the diversity of the American people.