Some states are seeking to block implementation of Obamacare in their states. Liberals sneer, "We already had the nullification argument in the 1860s, and your side lost."
These same liberals pass gay marriage and marijuana laws in defiance of existing federal law. How is the new marijuana law in Washington* not an act of nullification? It either seeks to supersede the federal law or it's pointless; I don't decide whether to murder people because of what laws my commonwealth** has on the books when the Federales continue to have anti-murder laws. Nobody smokes pot because their state won't hassle them when the Feds have locked them up.
We're all nullificationists now. Instead of half of us wanting to nullify the other half's laws, wouldn't things be a lot easier if we allowed for political devolution?
* I hate the term "Washington State" because it's unnecessary. There is no capital city called Washington anymore, and there hasn't been for over 100 years. In 1871 Congress merged the City of Washington with the Territory of Columbia and created the District of Columbia. Everything official in "Washington" is named for the district. Since there's no such thing as "Washington, DC," there's no need to differentiate the state.
** I live in one of four states named commonwealths, and a surprising number of people around here know that. They use the term regularly when others would talk of "the state."