Is it necessary for SCOTUS members to have respect for settled law even when/if they disagree with it? Shouldn't they?

So you would have Dredd Scott still be the law of the land?

No....their job is to interpret what the law says. Not to write laws....it should not matter what some other judge said. If it is just first judge is right....then why do we have repeals and SCOTUS at all?

The role of the Supreme Court in this system derives from its authority to invalidate legislation or executive actions which, in the Court’s considered judgment, conflict with the Constitution.  The idea that the federal courts, or the United States Supreme Court, has the authority to interpret the Constitution, and can decide if a law is constitutional or not, is unconstitutional. Unfortunately, that myth has been perpetuated by the courts themselves in the attempt to gain power and work towards a more centralized big federal governmental system. The Framers created a Supreme Court that was independent of the "political" branches and insulated from public opinion. The Supreme Court would be the intermediary between the people and the legislature to ensure that Congress obeyed the Constitution. That is their job and should be carried out from an apolitical position, however, that seems to no longer be the case. As always, just my opinion. :)