This FlackCheck.org video summarizes the findings of an Annenberg Public Policy Center of the University of Pennsylvania study of coverage of 38 instances of incivility on cable news across a ten year period.
This FlackCheck.org category contains examples of extreme or hyperbolic language used in political rhetoric.

Demeaning or Dismissive Language

Extreme attack on opposing position

Extreme characterization of a person or group

Extreme characterization of an agency/institution

Impugning Motives or Integrity

Inappropriate Comparison

Language of Violence