Has the Republican coalition run its course?

The coalition of social conservatives and business interests that helped the Republican Party may have run its course - and may have actually run it a few years back. But internal factors may make it difficult for the party to quickly shift its course.

Here's an argument that they may have painted themselves in a corner and suffer from the paradox of plenty, and one that suggests that the base may make it difficult for the leadership to make the shifts in policy that will expand its appeal to minorities.