He would not be the first person to try to get around a DUI that way. Most common though is driving a lawnmower. Are you suggesting red states are less likely to enforce dr*nk driving laws?
I dunno. Maybe less likely to call riding a horse a driving violation. In his final years my BILs dad bought a tractor and drive that out to th3 farm. The sheriff came and talked to him to convince him not to drive the tractor but never went any farther with it. Western Minnesota next to South Dakota.