The Supreme Court of the United States will rule on whether illegal drug users can legally possess firearms under the Gun Control Act of 1968’s Section 922(g)(3), a decision with sweeping implications for Second Amendment rights and federal-state tensions.

In a landmark challenge to federal gun-control law, the US Supreme Court has agreed to review whether the ban on firearm possession by illegal-drug users—under Section 922(g)(3) of the Gun Control Ac…