Republicans have worked hard to create a fictitious scapegoat known as "urban folks" whether its the white coastal elites with their bookshops and expensive coffee spots or the "inner city" non-whites with their poverty, crime, and high birthrate. Meanwhile the Democrats have, for the most part, done little to provide any positive messaging/specific policies to help the working class, especially the rural working class since like the New Deal it seems; instead, they just keep taking them for granted. That's my take.
It's more messaging than policy. As an example, when the Democrats have power in a state they tend to cut through the red tape and spend to make, say, Medicaid services easier to access and to provide higher quality services within a reasonable time frame. You'll find that
some of the folks that use those services in rural areas realize this and tend to vote Democrat.
The problem the Democrats run into is that the messaging actively hurts them with people that use the services but don't appreciate being equated with the urban poor (these are your latent racists) as well as the people that don't use those services and don't much care what happens to the less fortunate because of conservative ideology or latent racism. If the Democrats credit claim, their base already gets it, the people they're trying to win over directly with policy get mad and they exacerbate their problem with some people they're trying to win over with other policies.
It's a problem. In places where the Democrats do a good job with both messaging and policy, they tend to win more. They're pretty much locked out of power at the state level in a lot of places where they haven't done so well historically by way of gerrymandering, so they can't
prove much of anything via policy.