The US Constitution is followed because it states that the laws of the United States take precedence over state law the federal government contradict one another.
Step-by-step explanation:
The law of the United States is given preference over the law of any state in the country, a such, the US constitution is followed. For example if the law of Ohio allows bicycle users to ride along pedestrian ways, while the federal constitution states that cyclists should ride at the side of the highway.
In that situation, a cyclist is advised to ride beside the highway since the law does not agree with the law. Most times, in the state law, they may state their reason for doing so.