ValorousTFThey are literally funding people pushing the overton window to the right. I recall don't think right wingers mind that the Kochs fund them, politicians, think tanks, and media figures who basically agree with them on every issue. Idk, the American right is very far right. But what do I know?
From the perspective of someone who is probably considered "far right" I can confidently tell you that the overton window has not pushed to the right at all. All the Koch brothers really did was bankroll the republican party into becoming an ugly breed of TP:USA libertarianism and boomer conservatism.
The authentic right absolutely despise and blame them a lot for the society we live in today. They pushed for the right for women to have an abortion, they pushed for opening up borders to immigration, they pushed for the legalisation of (some?) drugs and essentially pushed the overton window to the left by integrating these typically left wing ideas into the republican party.
The whole overarching idea is that the Koch brothers are mainly responsible for damaging the authenticity of the republican movement and making it much more left wing as a whole.