Conflict theorists believe that essentially all aspects of our society are created through conflict. This conflict takes place between groups. The rich and poor come into conflict. Whites and non-whites come into conflict. Other conflicts occur as well. To conflict theorists, deviance is a result of conflicts between groups.
Deviance is an attribute that is socially constructed. That is, there is nothing inherent in an act that makes it deviant. Instead, acts are deviant or not deviant because society labels them that way.
Conflict theorists say that various groups compete to define what acts are deviant and what acts are not deviant. They say that the dominant groups in our society win this competition. These groups get to define what actions are deviant and what actions are not. This means that actions that are typically taken by people of the non-dominant group are more likely to be labeled as deviant than those actions that are more typically taken by members of the dominant group.
Therefore, for example, we could argue that the actions of the “Occupy” movement were labeled as deviant while those of the “Tea Party” were not. We can say that things like selling drugs (done more by poorer and non-white people) are labeled as deviant while things that bankers do are not.
Conflict theorists, then, would explain deviance by saying that deviance is socially constructed and that the dominant classes get to define what deviance is.