It was added to the Constitution to protect the people from the national government from having too much power. Adding the Bill of Rights helped change many people's minds to ratify the Constitution. The bill of rights protects the rights of people in the minority. The minority cannot have their rights taken away.
I hope this helps you.
The best first step is to acknowledge that they are upset. Have them sit down and explain. If they are speaking loudly, speak in a lower volume.