What does Dred Scott have to do with the Second Amendment? The non-permanent status of Supreme Court decisions.
Dred Scott was a slave brought to Northern States by his owner and went to a Missouri Court to gain his freedom. The case was taken all the way to the Supreme Court where the case was decided 7-2 against Scott; he was regarded as property and not a citizen. See "Dred Scott v. Sanford".
The case was essentially overturned by the Fourteenth Amendment, which included "All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside."
Furthermore, there was a 8-1 Supreme Court decision supporting segregation: Plessy v. Ferguson. The lone dissenter, Justice John Marshall Harlan "wrote that the majority's opinion would 'prove to be quite as pernicious as the decision made by this tribunal in the Dred Scott case.'"
"Plessy v. Ferguson" was overturned by the Supreme Court in "Brown v. Board of Education" in 1954 unanimously 9-0!
The Second Amendment was interpreted to apply specifically to individuals in "District of Columbia v. Heller". The case was decided 5-4 with the expected votes each way.
This is a case of "activist judges" interpreting the Constitution to match their political beliefs. From the "District of Columbia v. Heller" Wikipedia page we have:
Richard Posner, judge for the United States Court of Appeals for the Seventh Circuit, compares Heller to Roe v. Wade, stating that it created a federal constitutional right that did not previously exist, and he asserts that the originalist method – to which Justice Antonin Scalia claims to adhere – would have yielded the opposite result of the majority opinion.
The text of the amendment, whether viewed alone or in light of the concerns that actuated its adoption, creates no right to the private possession of guns for hunting or other sport, or for the defense of person or property. It is doubtful that the amendment could even be thought to require that members of state militias be allowed to keep weapons in their homes, since that would reduce the militias' effectiveness. Suppose part of a state's militia was engaged in combat and needed additional weaponry. Would the militia's commander have to collect the weapons from the homes of militiamen who had not been mobilized, as opposed to obtaining them from a storage facility? Since the purpose of the Second Amendment, judging from its language and background, was to assure the effectiveness of state militias, an interpretation that undermined their effectiveness by preventing states from making efficient arrangements for the storage and distribution of military weapons would not make sense.
End of extract.
Wikipedia has a good entry on the Second Amendment at en.wikipedia.org/wiki/Second_Amendment_to_the_United_States_Constitution.
So, how do these cases tie together? The decisions of the Supreme Court are no more permanent than the terms of office of politicians or the "to and fro" of public opinion. Some years for now, "District of Columbia v. Heller" may be overturned by a different court or another Constitutional Amendment.