Political discourse is an observable, measurable, and testable manifestation of political worldviews. However, when worldviews collide, notions of truth and of lies are put to the test. The challenge for researchers is how to establish confidence in their analysis. Despite the growing interest in deception research from a diversity of fields and industries, the trend is to focus on validating the assessment approach to the data without considering validity issues related to the data itself. Such a trend is concerned more with "how" to assess linguistic features and less with "what" is being assessed. By contrast, this dissertation is concerned with both the "how" and "what" of deception analysis. Of necessity, establishing validity of the data needs to be addressed first. To this end, I use the computational textual analysis tool of the "Gramulator" to facilitate validating a corpus of truthful texts and deceptive texts written by self-described liberals and conservatives. Specifically, I apply the "internal validity process" ("IVP") to the corpus. The IVP comprises rigorous validity assessments of the "homogeneity" and the "markedness" of the data as well as the derived indices. This process aims to validate "what" is being assessed (i.e., truthful texts and deceptive texts). I then use the Gramulator to analyze the corpus. Specifically, I conduct a "linguistic style matching analysis" and a "distal language analysis" of the corpus. The linguistic style matching analysis assesses the degree to which deceivers and truth tellers from divergent political groups coordinate their language. By contrast, the distal language analysis assesses the degree to which those same groups differ in their pronoun and pronominal usage. These analyses reveal "how" computational approaches in combination with linguistic theory facilitate deception analysis. The results of my dissertation suggest that the IVP supplies compelling evidence for the validity of the corpus. These results also suggest that linguistic style matching and distal language usage may be deception strategies used to influence others into a false belief. Taken as a whole, my dissertation offers greater insight into how subtle differences in the framing of word choices facilitate the identification of prominent features of deception in political discourse. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]