The answer from silentOpen is excellent, but I wanted to add a few things.
Hierarchy is the rule of men, not of laws. So even if there were a hierarchical relationship between bodies of law, that doesn't require a hierarchical relationship between people.
In the US, federal law can supersede state law, and state law can supersede county and city law. It does have to be written that way of course. In practice, many laws are written to allow jurisdictions to self-regulate within broad limits. For example, in California it's legal to open a marijuana store. But localities get to decide whether it happens in their city. And it's technically illegal federally, but that's currently unenforced.
But the president has no direct authority over governors, and governors have no direct authority over mayors. However much Trump dislikes a variety of San Francisco policies, he cannot just order them changed. Instead he would have to persuade both the House and Senate to pass a law, and San Francisco could challenge that law in the courts.
Hierarchy is the rule of men, not of laws. So even if there were a hierarchical relationship between bodies of law, that doesn't require a hierarchical relationship between people.
In the US, federal law can supersede state law, and state law can supersede county and city law. It does have to be written that way of course. In practice, many laws are written to allow jurisdictions to self-regulate within broad limits. For example, in California it's legal to open a marijuana store. But localities get to decide whether it happens in their city. And it's technically illegal federally, but that's currently unenforced.
But the president has no direct authority over governors, and governors have no direct authority over mayors. However much Trump dislikes a variety of San Francisco policies, he cannot just order them changed. Instead he would have to persuade both the House and Senate to pass a law, and San Francisco could challenge that law in the courts.