Some things to consider about Stephen Colbert and the character he portrays:
He's played this character before, on the Daily Show of course, but also on other projects he's been involved with. In Wigfield his character is similar to the character he plays on the Report:
http://www.amazon.com/review/R2XH1N0DQJVUM4/ref=cm_cr_rdp_perm
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So, it's not as though he just got roped into the character, it's something he's been loosely working on for years, that doesn't mean he wasn't still surprised by the success of the Report. And in Strangers with Candy (it's on hulu somewhere) he played an odd sort of guy too, also the type who was selfish and vain.
But, I think the biggest motivation behind this character comes from the time Colbert spent at Hampden-Sydney College - which is:
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"one of only three remaining traditional ALL-MALE colleges...mission is to "form good men and good citizens in an atmosphere of sound learning." … has one of the strictest Honor Codes... as a student, each man pledges that he will not lie, cheat, steal, nor tolerate those who do; this pledge is binding for life. The pledge takes place during a ceremony conducted in the campus church.
Every student must pass the Rhetoric Proficiency Exam, a three-hour essay graded upon coherence and quality of argument, style presented, and grammatical correctness.... the college requires two Rhetoric classes that are taken the first two semesters...
...students are Southern, well-dressed, articulate, conservative. Many take part in campus traditions—jacket and tie to football games, greeting everyone met on campus, They are given “To Manner Born To Manners Bred: A Hip-pocket Guide to Etiquette for the Hampden-Sydney Man,” which covers everything from basic manners, how to greet and introduce people, how to respond to invitations, etc
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I think the Report character is a satirical mash-up of the culture at Hampden-Sydney...
food for thought for deconstructing the Report character
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