Does congressional legislation in harmony with the Constitution supersede state laws? Yes! They automatically become part of the "supreme law of the land," and consequently, supersede all state laws to the contrary. But when the checking power of the three federal branches don't prevent laws that exceed their constitutional limitations, the Founders reserved to the states the power to nullify them by refusing to enforce them within their states.
The greatness America has enjoyed is not because of what government officials did, but what the Constitution prevented them from doing. Thomas Jefferson warned that we should "bind them down from mischief with the chains of the Constitution."
Alexander Hamilton wrote: "No legislative act, therefore, contrary to the Constitution, can be validated," and are "merely acts of usurpation."
James Madison stated: "The state legislatures will jealously and closely watch the operation of this government, and be able to resist with more effect any assumption of power than any other power on earth can do ... the state legislatures [are] to be sure guardians of the people's liberty."
One of the best examples is the Kentucky and Virginia Resolutions in response to the Alien and Sedition Acts (1798, 1799). They authorized Congress to punish critics of the president, which violated the First Amendment's guarantee of freedom of speech. They enabled Congress to punish crimes other than those the Constitution authorized. The Resolutions declared that any state legislature had the authority and duty to disregard the unconstitutional Acts.
The Kentucky Resolution stated that "undelegated" federal powers are "void, and of no force," and that "this government ... was not made the exclusive or final judge of the extent of the powers given to itself."
Utah's state legislature has authority and duty to refuse to enforce unconstitutional federal legislation regarding gun laws, Obamacare, the Patriot Act, and the National Defense Authorization Act for indefinite detention of suspected terrorist (including American citizens), without due process, to mention a few.
Our non-negotiable state's rights (Tenth Amendment) belong to the citizens of Utah, not our state representatives, who are unauthorized to waive them in exchange for federal funds.