There is not much room for disagreement on this. I would normally let this go, but if you tell people who know anything about the law (that aren't politicians promising things they can't deliver on) that states can nullify federal marijuana law, people will judge you and not take you seriously.
The only successful nullification of federal law occurred in 1798, when the Kentucky and Virginia legislatures passed resolutions saying that the Federal Government's Alien and Sedition Acts were unconstitutional because they
trampled rights expressly listed in the bill of rights and
the federal government lacked the authority to legislate in this area.
It is important to look at those resolutions in context. Prior to Marbury v. Madison, 5 U.S. 137 (1803), people were not not sure who had the final right to review the constitutionality of law. SCOTUS held in that case that the Supremacy Clause of the U.S. Constitution makes federal law superior in effect to state law and established SCOTUS as the final interpreter of federally guaranteed rights and laws.
It is emphatically the province and duty of the Judicial Department to say what the law is. Those who apply the rule to particular cases must, of necessity, expound and interpret that rule. If two laws conflict with each other, the Courts must decide on the operation of each.
So, if a law be in opposition to the Constitution, if both the law and the Constitution apply to a particular case, so that the Court must either decide that case conformably to the law, disregarding the Constitution, or conformably to the Constitution, disregarding the law, the Court must determine which of these conflicting rules governs the case. This is of the very essence of judicial duty. If, then, the Courts are to regard the Constitution, and the Constitution is superior to any ordinary act of the Legislature, the Constitution, and not such ordinary act, must govern the case to which they both apply.
Those, then, who controvert the principle that the Constitution is to be considered in court as a paramount law are reduced to the necessity of maintaining that courts must close their eyes on the Constitution, and see only the law.
This doctrine would subvert the very foundation of all written constitutions.
This piece of history is important because it occurred after the Virginia and Kentucky resolutions. Those resolutions were essentially states attempting to assess whether or not they thought a law was constitutional. They were trying to do the job of a post Marbury SCOTUS.
Since then, nullification has repeatedly failed. For example, in 1833 South Carolina passed the Ordinance of Nullification, which nullified two tariffs. Congress responded by passing the Force Bill, which essentially gave President Jackson the ability to use force against states that refused to comply with federal law.
Many, myself included, believe that the Nullification Crisis was the spark that set the south down the road to succession. The civil war dealt another blow the nullification movement. This is because nullifying a law doesn't mean anything if the nullifying party cannot protect itself from enforcement.
Nullification supporters say that the 10th amendment provides states with the ability to nullify federal law, because the constitution doesn't say that state's can't nullify federal law. The issue with this is that the supremacy clause says that federal law reigns supreme over state law. This means that if the federal government is validly exercising its authority then the states must follow it. The 10th is only used to day to prevent Congress from abusing its power under Article I Section 8 Clause I, the general welfare clause. This abuse occurs when a federal law removes states ability to make their own decisions through coercion. Most recently, SCOTUS held that the ACA/Obamacare's Medicaid expansion violated the 10th amendment because the spending provision rendered the states' ability to reject the provision illusory.
The point of this, is that valid federal law can be enforced in states that disagree with that law, because federal law supersedes state law.