US political parties are not symmetrical

Just because our two major political parties are the dominant ones does not mean that they are symmetrical. Krugman wondered yesterday about why the symmetry error persists. Apparently, the assumption of symmetry is common among political scientists. I'm really surprised by this. I'm also a little surprised that Krugman is unable to see the nature of the asymmetry. He writes:

[I]t is a puzzle. I do think that wingnut welfare is part of the story. But there has to be more. Any suggestions from real political scientists would be especially welcome.

So ... I am so far away from being a real political scientist.

But this seems pretty simple to me. Krugman quotes a recent paper by Grossman and Hopkins, who "argue that the Republican Party is the agent of an ideological movement, while the Democratic Party is best understood as a coalition of social groups."

Right. Republicans are ultimately organized around protecting existing cultural advantages, and the monetary advantages of a few. Because the "few" are very few in number, a broader coalition is required, one that finds common cause around avoiding loss and maintaining existing cultural advantages, regardless of any change that might be occurring in the world. They are like the "elders" in this post. Keeping that coalition together is very hard, mostly because it's deeply self contradictory (someone please ask the GOP candidates how they square their campaign rhetoric on foreign and domestic policy with Jesus' radical challenge in Matthew 5:39, or Paul's admonition about law suits in 1 Corinthians 6:7). So it requires strict ideological adherence, with the carrot of "some day, you too could be filthy rich." (The recent disruption of the GOP might be due to the fact that the carrot has turned out to be pretty dried out and rotten.)

Democrats on the other hand, by default, represent a broad coalition of social groups with an interest in establishing fundamental cultural institutions that serve much broader interests. Ideological adherence is not compatible with the role that the Democratic Party plays because the platform necessarily must be built on compromise.