The chart plots social liberalism/conservatism and economic liberalism/conservatism at right angles, creating four quadrants. You can, in principle, fall anywhere on the chart. (Libertarians, with an uppper-case "L", place themselves in the economic conservative, socially liberal quadrant.)
The National Journal rates congresscritters in terms of liberal vs. conservative in three broad areas – economics, foreign policy, and social issues. The correlation between economic conservatism and social conservatism is
0.895971914, and here's what it looks like:
First, it appears a lot of people are willing to run all the way to the non-conservative side of the economic scale, but no one wants to go all the way to 100% conservative.
Second, there are large circular holes in the distribution where no one cares to go. The Libartarian region (lower right) and Fascist region (upper left) are empty.
It would appear that while it's possible to be Libertarian or Fascist, it never happens in American politics.
So much for the Nolan chart?