A proposal in the Texas Legislature calls for the state to - through a legislative process - ignore federal law and court rulings, and forgo enforcing national regulations. The Texas Sovereignty Act allows for overriding federal laws through the same process as passing a bill. First a legislative committee, then the whole Legislature, would vote for nullification, and then the governor would sign his approval.
Texas has a unique ability to trail-blaze on the issue of nullification because its constitution reserves the right to revert to a sovereign nation, something no other state's constitutions enshrine.
That said, the issue of nullification truly needs to be addressed at the state level. While some locales and states are ignoring federal law via their declarations of "sanctuary cities," using the activist courts to execute their defiance, that kind of activist avenue open a Pandora's box. Why couldn't states and locales that disagree with Obamacare do the same thing; refuse to acknowledge the federal law?
Nullification, on the other hand, restores the check and balance of power the states lost with the 17th Amendment; the direct election of US senators. The Constitution originally saw the Senate as a body that protected the rights of the states with each state's senators appointed by the state legislatures. Easily recallable, these emissaries were more concerned with the well-being of their own states where federal laws was concerned than their political parties.
Watch Texas on this...they have the right idea.