They are quite aware of taxes because 13.5% of their income on average comes directly from federal subsidies paid by taxes on "city folk".
https://usafacts.org/articles/federal-farm-subsidies-what-da...
> The voters will vote against their own interests over and over and over if they keep hearing something that resonates with what they feel.
Most large farm owners are very well off and are absolutely voting in their own interests for the party whose primary goal is to cut taxes on the wealthiest while cutting government support for the poorest.
The rural working class and poor on the other hand are however often voting against their economic interests, but their economic situation has long been ignored by both partie, so having given up hope for economic change, they often vote on culture/identity issues.