Liberal economic populism's diminishing appeal to rural voters

[Dgov]

I think you missed a big one which is "Increasing governmental influence in their lives".  Supporting big government ideals was great back in the 30s, 40s, and 50s, when they were basically the government giving them money.  But nowadays, the government is passing laws regarding land use, environmental legislation, and other things that interfere with how rural voters have lived their lives for 2 centuries, and that's a big turnoff for interventionism.  There's a reason the Republican's message on big government doesn't solely revolve around tax rates.