It has become an axiom in today’s politics that Washington is increasingly, intolerably and perhaps permanently polarized, that the two major parties are moving toward their ideological extremes, and that the result is legislative paralysis and really ugly politics. There is a lot of truth in that sentence.

But it misses a critical internal debate in which dissenting groups in each party are challenging that party’s economic orthodoxy. I’ll outline those changes in this post, and look more closely at each in the days ahead. I welcome your thoughts.

On the Republican side, the tendency to lump together Tea Partiers and cultural conservatives – while dismissing Ron Paul as a libertarian outlier – has shed insufficient light on what is driving bitter rivals to pummel Mitt Romney as much for his persona as his politics. One clue lies in the success of Richard Nixon’s “southern strategy,” which attracted to the GOP millions of disaffected Democrats, They were not simply nostalgic for the Jim Crow south or fed up with the 1960s. They were also heirs to an agrarian, and often angry, economic populism, which meshed with similar beliefs held by generations of western and midwestern Republicans. One result was to vastly expand the wing of the party that detested “Wall Street” and its bankers, financiers and internationalist worldview.

Meanwhile, the reigning Democratic ideology equates social justice with economic growth, a position that resonates with the party’s dominant interests – labor unions, entitlement recipients and minorities seeking opportunity. Environmentalists, however, are increasingly raising fundamental questions about both the possibility and the desirability of unlimited growth.