In this scheme, what prevents a central bank from abusing its position and denying you access to food due to ideological concern? Cash (for basic stuff) spends

In this scheme, what prevents a central bank from abusing its position and denying you access to food due to ideological concern? Cash (for basic stuff) spends the same regardless of my political affiliation or criminal history. An employer can do the same, but I can get a new employer with some effort. I'm not sure I can switch to a different central bank easily.