do us supreme court decisions have the force of law? absolutely!!! what the supreme court decides is final. unless, of course, it changes its mind. there've been numerous times when it has (e.g., thankfully taney's court that ruling on dredd scott in 1857 was subsequently overturned as our understanding became more humane and our economy opened up to a new form of, a truer, form of democracy). i think that it was during the andrew jackson administration when president jackson was clearing out native american homelands, moving them to west of the missouri or mississippi river. i think that it was the cherokee nation that filed suit claiming that it was unlawful for president jackson to move them against their will. the supreme court agreed. president jackson said something like, "fine, let the supreme court come and enforce their decision". of course, the supreme court couldn't really enforce its decision - it has, what, 100 security guards? they could never take on other agencies, literally, those agencies need to legally defer to the supreme court. same way with many of its findings during wars, its waited to rule against the president until after the war, presumably so that the war is not interfered with. so, while the supreme court decisions have the force of law, it only does so when the executive and legislative branches defer to the judicial branch, which, on occasion, it hasn't. in those times, i wish we had a constitutional amendment that gives the supreme court the ability to demand enforcement of the rule of law.

Yes and no. There is no federal common law (like there is in state courts), but a Supreme Court interpretation is the "correct" interpretation of a law. Thus, the decision is binding, but not because the SC has the power to pass laws, but because the law they are interpreting is binding. For example, suppose Congress passes a law that says all animals who are transported between states must be licensed before transport. Now suppose the Supreme Court interprets that law to mean only "farm animals" and domestic animals are excluded. Thus, that law now only means "farm animals." However, Congress can always amend the law to clarify that it does include domestic animals, in which case the SC decision is moot. On the other hand, when the SC interprets the Constitution, Congress is powerless to overrule. Thus, in a sense the SC can make law. For example, there is nothing in the Constitution that guarantees a persons right to an abortion. However, the SC has interpreted that the Constitution does provide such a right. This is essentially legislation, even though it is couched in "interpretation." employers military style guns sold in interstate commerce must be registered with the federal government.