Michael Lind is the author of Land of Promise: An Economic History of the United States and co-founder of the New America Foundation.

In understanding the polarization and paralysis that afflict national politics in the United States, it is a mistake to think in terms of left and right. The appropriate directions are North and South. To be specific, the long, drawn-out, agonizing identity crisis of white Southerners is having effects that reverberate throughout our federal union. The transmission mechanism is the Republican Party, an originally Northern party that has now replaced the Southern wing of the Democratic Party as the vehicle for the dwindling white Southern tribe....

The white Southern narrative — at least in the dominant Southern conservative version — is one of defeat after defeat. First the attempt of white Southerners to create a new nation in which they can be the majority was defeated by the U.S. Army during the Civil War. Doomed to be a perpetual minority in a continental American nation-state, white Southerners managed for a century to create their own state-within-a-state, in which they could collectively lord it over the other major group in the region, African-Americans. But Southern apartheid was shattered by the second defeat, the Civil Rights revolution, which like the Civil War and Reconstruction was symbolized by the dispatching of federal troops to the South. The American patriotism of the white Southerner is therefore deeply problematic. Some opt for jingoistic hyper-Americanism (the lady protesteth too much, methinks) while a shrinking but significant minority prefer the Stars and Bars to the Stars and Stripes.

The other great national narrative holds that the U.S. is a nation of immigration, a “new nation,” a melting pot made up of immigrants from many lands. While the melting pot story involves a good deal of idealization, it is based on demographic fact in the large areas of the North where old-stock Anglo-Americans are commingled with German-Americans, Polish-Americans and Irish-Americans, along with more recent immigrant diasporas from Latin America, Asia, the Middle East and Africa.

But even before the recent wave of immigration from sources other than Europe, the melting pot never included most of the white South....