Christopher Caldwell explores the American partisan political divide in the latest edition of Hillsdale College’s Imprimis.

American society today is divided by party and by ideology in a way it has perhaps not been since the Civil War. I have just published a book that, among other things, suggests why this is. It is called The Age of Entitlement: America Since the Sixties. …

… it is a third strand of the story, running all the way down to our day, that is most important for explaining our partisan polarization. It concerns how the civil rights laws of the 1960s, and particularly the Civil Rights Act of 1964, divided the country. They did so by giving birth to what was, in effect, a second constitution, which would eventually cause Americans to peel off into two different and incompatible constitutional cultures. This became obvious only over time. It happened so slowly that many people did not notice.

Because conventional wisdom today holds that the Civil Rights Act brought the country together, my book’s suggestion that it pulled the country apart has been met with outrage. The outrage has been especially pronounced among those who have not read the book. So for their benefit I should make crystal clear that my book is not a defense of segregation or Jim Crow, and that when I criticize the long-term effects of the civil rights laws of the 1960s, I do not criticize the principle of equality in general, or the movement for black equality in particular.

What I am talking about are the emergency mechanisms that, in the name of ending segregation, were established under the Civil Rights Act of 1964. These gave Washington the authority to override what Americans had traditionally thought of as their ordinary democratic institutions. It was widely assumed that the emergency mechanisms would be temporary and narrowly focused. But they soon escaped democratic control altogether, and they have now become the most powerful part of our governing system.