The government powers on a national level is always above the state laws. The nation gets its powers from the constitution which was designed to protect people and states while centralizing and giving more power to the federal government which deals with issues on a national level and makes new legislature.
The state powers used to be bigger but have been reduced. However, the states have sovereignty to make laws of their own that only apply in their own areas and these laws can exist as long as they don't oppose the federal laws that have to be obeyed by everyone. The state sovereignty is highly limited and they can't do as they wish.
