What is the current state of the law on firearms possession in drug trafficking cases?

Defendants who use or carry a firearm "in furtherance of" a drug trafficking crime face certain mandatory minimum sentences. 18 U.S.C. 924(c). "[T]he mere presence of a weapon at the scene of a drug crime, without more, is insufficient to prove that the gun was possessed in furtherance of the drug crime." United States v. Snow, 462 F.3d 55, 62 (2d Cir. 2006) (internal quotation marks and emphasis omitted). Instead, there needs to be a "nexus" between the possession or use of the gun and the furtherance of the crime. Id. "Ultimately, the test is whether a reasonable jury could, on the evidence presented at trial, find beyond a reasonable doubt that possession of the firearm facilitated a drug trafficking crime" by "afford[ing] some advantage . . . relevant to the vicissitudes of drug trafficking." United States v. Lewter, 402 F.3d 319, 322 (2d Cir. 2005).