If so many people have the same opinion, does that make it right?

Lots of people hold each of the following opinions:

• Christopher Columbus was a murderer and a bigot.
• Abraham Lincoln was a hero and a savior of our country.

There are many other figures in American history that are viewed in similar ways.  There are lots of people in history that everybody seems to love and there are lots of people that everybody seems to hate.

How do we deal with that?  Should we go along with the prevailing opinion?  Should we oppose it for the sake of opposing it?  How should we think about people and their historical contributions?