The Republican base is being supplemented by older generations shifting away from the Democrats, which might have some interesting ramifications for republican policy:
In a way, these figures should make small-government conservatives a lot more nervous than they make partisan Republicans. After all, you can win an awful lot of elections just by mobilizing the over-65 constituency — they’re well-informed, they turn out to vote, and there are more of them every day. But the easiest way to do it, as the Democrats proved for years and years and years, is to defend Medicare and Social Security like McAuliffe at Bastogne. This means that while the energy of activists may be pushing the Republicans to the right on size-of-government issues, the concerns of their central constituency could end up pulling them inexorably leftward on entitlements. (There’s a reason that even South Carolina’s Jim DeMint, in the midst of a CPAC stemwinder, paused to allow that one of the things government “has” to do is “keep our promises to our seniors.”)
I had a different read of the situation (but my intuition about the aging base seems right.