In the context of changing policies in a public school, the most relevant government leader would typically be a state representative. Education policy is primarily governed at the state level, and state representatives can influence legislation related to public schools, such as funding, curriculum standards, and educational reforms.
While the president may have some influence through federal education policies and funding, most direct control over public school policy lies with state and local governments. The Supreme Court can impact education through judicial rulings on cases that challenge existing laws or policies, but they do not create or change school policies themselves.