Stare decisis, it's a principle adopted by SCOTUS, it's not in the Constitution. It simply means a previous decision should be given great weight and not over turned unless it's quite clear it was wrong, say Pessy-v-Ferguson for example.
Interestingly, the Constitution doesn't explicitly give SCOTUS the power to "interpret" the Constitution. That came about after Marbury-v-Madison, in effect (or most clearly).