It’s part of a broader trend in conservative circles of wanting to go back to a prelapsarian constitutional order, whether that’s wanting to go back to the pre-Warren Court order (here, Brown v. Board tends to take a back seat to things like Grey v. Sanders and Baker v. Carr), or wanting to go back to the pre-New Deal order (here, the key thing is wanting to go back to Lochner era restrictions on the ability of government to regulate the economy), or in some cases, wanting to go back to a pre-Progressive Era order.
This last variant ties together the expansion of democracy – both in the inclusion of women and the adoption of more direct democratic forms – with the expansion of Federal power, and argues that if we go back to state legislatures electing Senators instead of the masses, then not only will that empower state governments against the Federal government, but it will also tamp down on populist demands for the government to violate property rights by regulating against sawdust in bread and mandating fire escapes on factories.
Up until recently, this was considered a very fringe position to take, but after the emergence of the Tea Party we’ve seen Republican nominees for elected office…including the U.S Senate, ironically, take this position. It doesn’t tend to do well, because it’s generally a hard sell to voters that you want them to have less rights and less power.