If you see a huddle of parents away from the stands with their arms crossed and they don't smile very often, stay away from them. This is the "politics" crowd. They know everything. They alternately award themselves the title of Mr. Baseball. They know more than the coach. They know more than anyone about who should be playing.
I was warned about politics when my son was in middle school and on JV's his freshman year. When he started as a soph the only politics I heard about were the ones I supposedly played to have him be the first soph to start opening day in six years. The dad of the first freshman to ever start opening day heard the same thing. What the complaining parents overlooked was our kids had been playing up in travel for two years and already made 18U scout teams for the upcoming summer.
"Politics" happen to marginal players. The "politics" are the coach decided the player other than the complainer's son has better potential. I've never heard screams of politics from the parents of obvious starters.
Relax. Tell your son to work hard. Have him read How to Make the High School Team.