True. This goes back to the pre-WW2 days when the Democrats enacted a New Deal that was really a massive redistribution of wealth from the Northeast to the South in this country. If this is the kind of thing you have in mind for the Republican Party, then you might as well shut the party down because you've turned it into nothing more than a tool of economic leverage.
But then again, Clinton carried several Southern states. So don't assume that if cultural values can be neutralized (say, by a conservative Supreme Court that will not impose California values on Georgia or vice versa) as a national issue that a Southern democrat talking economic populism couldn't repeat that.
The very nature of Bill Clinton's election in 1992 should always be seen as an anomaly, and we should avoid deriving any conclusions from that election. Clinton won the following Southern states in 1992: Arkansas, Georgia, Kentucky, Louisiana, Missouri (I'll consider this "southern" for the sake of this discussion), and Tennessee.
Of these states, Clinton only received a majority of the vote in his home state of Arkansas (53%). He won all of those other states simply because of Perot's third-party influence on the election (including Missouri, where Clinton got 44% of the vote and Perot got a very high 22%). The Clinton-Gore ticket couldn't even win a clear majority in Gore's home state of Tennessee (they got 47%).
To illustrate just how odd those election results were, just consider this: in at least two of these states (Missouri and Tennessee) Clinton actually got a smaller share of the votes in winning the state in 1992 than Gore got in losing it in 2000.
Let's talk about Perot.
Perot pointed the way to the politics of the future. Economic nationalist, culturally populist. The William Jennings Bryan of the late 20th century. If the Dems are smart enough to let the sodomites and decadents split off into the Greens and restore economic populism as their centerpiece (in effect, admit the McGovern reforms were a terrible mistake) they could get it back.