Which branch of government makes sure bad laws aren't made?

Answer 1

The Judicial Branch, although their task isn't to search for fairness, only for the constitutionality of a law.

Any court, but particularly the US Supreme Court, can review laws relevant to cases being tried or appealed before that court to ensure their constitutionality, but they don't scrutinize them for "fairness," as most people would define the concept.

Many laws are unfair to certain people or groups, but the judicial system is only concerned with whether a law is faithful to constitutional principles.

In order to overturn an "unfair" law, someone first has to convince the Court that the law directly violates a real person's (or people's) constitutional rights and causes harm to that person (or people). Even then, the courts may uphold a law that seems unfair, and may be arguably unconstitutional, if the government can demonstrate the law serves a compelling and legitimate government interest and is written narrowly, so that it accomplishes its purpose with as little negative impact as possible.

Answer 2

Judicial makes sure they follow the Constitution and that they are fair.