What does it mean to show bias?

Citizens of the Fairlawn Park area, look with alarm at the evil plot to change a beautiful spot into a baseball park. If this malicious plan is carried out, the lovely trees in the park will be chopped down. Values of the property within the area will drop sharply as the park fills with the filth and debris of the bulldozers and other equipment. Later the shrieks of the young ruffians who take over the park will destroy the peace and quiet of the neighborhood. Obviously no one cares about the poor citizen who has slaved to pay for his home and to keep up with his taxes.

The author is biased against...

What word is used to describe a text that contains NO bias?