Re: Motorcycle Headlight Modulator
the Supremacy clause does not apply. You are misunderstanding the supremacy clause. As an example of laws that are clearly in contrast of each other yet each is considered valid, check out any state that has a medical marijuana law. They are in direct contrast of the federal law yet they are quite accepted and acceptable as a state law. It is only when there is a conflict between the application of the laws does the supremacy clause come into play.
In other words: the feds can come in and enforce their MJ laws in any state that has a MM law as long as they prosecute under the federal statutes. The state can refuse to enforce the federal statutes and enact their own laws which are more lenient.
There is nothing that states a federal and a state law cannot co-exist although they are in contrast to each other. The supremacy clause goes much deeper than simply saying the federal statutes override state statutes.
What we have here is a safety standard, not a law per se but a requirement within a law. If the feds allow something, a state cannot disallow that same thing but as to the requirements of the state law being identical to the federal reg, not true.
The state reg cannot disallow something the fed allows nor can they lower the standard the feds set but the state can require a higher standard.
However, the United States Government, a State, or a political subdivision of a State may prescribe a standard for a motor vehicle or motor vehicle equipment obtained for its own use that imposes a higher performance requirement than that required by the otherwise applicable standard under this chapter.
I am not an attorney and any advice is not to be construed as legal advice. You might even want to ignore my advice. Actually, there are plenty of real attorneys that you might want to ignore as well.