How do the terms pluralistic and consensus both apply to american society?

The term pluralistic soicety is used if there is more than one group of people exist within a society, and the term consensus is used if all members in the society acted based on pre-determined agreement on what is acceptable and what is not

American society is pluralistic-because there are groups consisting of different cultures and ethnicity in the group.

And it considered as consensus because we acted based on laws that made through democratic process.