The Constitution is the topmost Federal Law. And its main purpose is to impose restriction on government.
Wrong The purpose of the Constitution was to create the new federal government, not to put limits on it. You cannot put limits on a government which you haven't created yet. OK, you could say---but only in a roundabout way---that it was intended to do both, but that's because the Bill of Rights is, technically, part of the Constitution, and it is those particular additions to the constitution that put limits on the government created in Articles I through VII. (the original document).
The constitution is pretty specific that it's the supreme law of the land. Even after Marbury v. Madison, the Supreme Court was still interpreting the constitution that the limits placed on it, and its sphere of authority, was typically the bailiwick of the national (federal) government. When a plaintiff in Barron v. Baltimore argued that the State of Maryland owed him money because his business was ruined by the actions of the city government of Baltimore---the V Amendment includes a clause that prohibits the government from seizing private property without compensation---the USSC's response was essentially: yes, that was a violation of the V Amendment and the State of Maryland WOULD owe you some cash....however, the V Amendment to the UNITED STATES constitution contains that, and it only applies to the Federal Government, not the government of Maryland (or Baltimore). The only way Charm City would have to pay you is if there were something in the state constitution similar to that in the US V Amendment. Since there isn't, we're afraid you're screwed. (It somehow slipped the minds of the conventions which wrote our Constitution of 1776 to put that in there...oops)
Essentially, Barron v. Baltimore ruled that the bill of rights and other limitations on the federal government within the US Constitution, are limits on the authority of the FEDERAL government, not the States. Only rights enumerated within the state constitutions (the first 10 pp of the Maryland constitution is entitled "Declaration of Rights", and it's more extensive than the US bill of rights) protect their respective residents against acts of the state governments. It was not until just before the second world war, if I remember correctly, that this view was abandoned in favor of the present view of federalism in the US, that the federal courts and government have the nearly unlimited authority to interpret not only the federal constitution, but state and local constitutions and laws as well.
So, where the state & local governments were once protected from the intrusion of the feds, they are no longer (since the principle works both ways). The answer, Brad, is yes, the states and localities must follow federal law.
And why shouldn't they? As much as I believe that diffusion of power is a good thing, too much of any good thing is a bad thing. In the 21st century, to have a constitution like our first (the Articles of Confederation and Perpetual Union Between the States of....) where the states retain such sovereignty as to be able to literally ignore the Congress of the United States would be an unmitigated disaster.