You are describing the President of the United States. As our commander and chief he is responsible for leading the executive branch of government. He is the head of the government and can make executive orders, meaning he does not have to answer to any legislative body. At the same time, there are checks and balances between the President of the United States and Congress. This makes it so that the president doesn’t end up being a dictator.
Laws that a judge finds to be conflict with the conflict with the U.S. constitution are referred to as "unconstitutional laws" These can be struck down in the Supreme Court.