Moving Towards Purple, Again

I wrote before on the decline of Democrats on County Commissions in NC here and here.  The story there was that all of the focus on the national level has missed the real story in North Carolina: that North Carolina is a divided state that has been moving towards purple for a while.  It therefore shouldn't be surprising when Obama wins the state, but the Republicans keep a number of important seats in Congress.  I have been wanting to simulate this analysis with the General Assembly for a while, but state legislative historical data are surprisingly hard to come by.  Fortunately, Jeff Stonecash at Syracuse was kind enough to send me his data from 1901-2008.  I cleaned it up in a few places, added the last few elections and here's the result:

The bumpy lines are the actual percent Democrat in the state Senate and House.  The smoothed lines with the long title (sorry--I meant to change it, but didn't have time) represent a fancy way to smooth the data so it's easier to see the trend.  This is interesting in isolation, but it's even more interesting when we compare it to other states around us.  Consider South Carolina:

How's that for a nosedive?  I think the Palmetto state left purple behind a while ago.  Looks pretty red to me.  Also, for historical comparison, look how strongly Democratic it was until the 1960s--we're talking 100% Democratic. 

Most of the South looks similar, but check out this weird outlier: West Virginia:

Somehow the Democrats have gained ground in WV.  I know WV isn't really the South, but I still find this surprising. My friend and colleague Roger suggested that it has to do with the lack of race being an issue in WV, or perhaps with the industrial (instead of agricultural) base of the state's economy.  Gibbs wondered about the influence of the Byrd machine.  I'm not sure the reason, but I sure find it interesting.