The "Supreme Court", How Supreme?

One of the most important issues of our time follows. We must understand this well. Dred Scott v. Sandford, (1857), also known as the Dred Scott Decision, was a ruling by the U.S. Supreme Court that people of African descent brought into the United States and held as slaves (or their descendants, whether or not they were slaves) were not protected by the Constitution and could never be U.S. citizens.  This was obviously the wrong ruling of the court and needed to be overturned. However, now a days we have Democrats running around saying every judge appointed to the Supreme Court must support previous court rulings in the case of abortion rights. Imagine if they said this in the 1800s.