Polarization in American public life is based on identity politics. That is, we Americans are more divided over who we think we are than over what we think needs to be done.
This isn’t anything new. We’ve always been more divided over race, religion, ethnic culture and region than over econom.
Or rather, clashes over economic interests have taken the form of clashes over race, religion and regionalism. For example, the antagonism between native-born Yankee Protestants and immigrant Irish Catholics was not over questions of theology.
During the Gilded Age period lasting from the end of Reconstruction to the beginning of the New Deal, the Democratic Party got the votes of Southern white people, Catholics and Jews, and the Republican Party the votes of Northern white Protestants, plus African-Americans in the parts of the country where they were allowed to vote.
Even when I was growing up in the 1940s, Jews and Catholics were barred from many elite clubs and college fraternities. Most universities had quotas on the number of Jewish students that could be admitted.
It was taken for granted that no Catholic, no Jew and no white Southerner could be elected President, let alone a woman, an African American or an atheist.
During the Gilded Age, leaders of both political parties were committed to support of corporate business and suppression of organized labor.
Bribery and corruption were common and out in the open. So was election fraud.
Class warfare during that era was actual warfare. The most extreme example was the Battle of Blair Mountain in West Virginia in 1921, where coal company supporters bombed militant coal miners from the air.
But none of this produced a realignment between Democrats and Republicans. Opposition to corporate domination, such as it was, took place within the two political parties or, more rarely, through short-lived independent parties.