The GOP is aging, too. At some point they are going to have to revitalize their recruiting efforts to compensate for the flight of the old & dying. Those who come up in the Republican Party of the future will be less White, and won't be as connected socially to WWII or the Great Depression. At this point to guess what the GOP of the future will look like, though, is a roll of bones.
I think the GOP is a party in transition. Some are saying the Reagan Era has come to an end, which may be descriptive, but also, and more relevant, the Bush Era most likely has come to an end. The nationalization of money sweeping across the planet underscores than in an anxious way.
My fear is that all the circumstances are fueling a Fundamentalist Christian social/political revolution. And they've got Armageddon on the brain. I wish instead that the Libertarians were gaining more traction within the Republican Party, or other secular moderates.