Republicans don't watch baseball.
"Umpires don't make the rules; they apply them."
Have any of the Republicans repeating this talking point looked at the strike zone over the last 50 years? Or how about how often fielders making a double play actually make physical contact with second base? I'm sure bigger baseball fans than myself could name a dozen more rules that Umpires traditionally bend or broadly reinterpret.
A consensus of umpires over time subtly changes the rules, while retaining their spirit, in order to keep the game enjoyable in the face of changing styles of play. Umpires operate on a combination of written rules and a constantly evolving professional baseball tradition.