Having previously worked for three years as a writer and story editor on King of the Hill, Cenac garnered public attention in a The Doomed Planet comedy sketch in which he did an impression of then-senator Barack Obama, discussing possible campaign posters. He was considered to become a cast member on Saturday Night Live in which he would have portrayed the Democratic presidential candidate, but was passed over in favor of long-time cast member Fred Armisen.
In June 2008, Cenac was hired as a correspondent and writer on The Daily Show with Jon Stewart. After making several comedic appearances along with other correspondents, Cenac filed his first field report on July 21, 2008, concerning Democratic Presidential nominee Barack Obama. He continued to integrate satirical Black-oriented material in his Daily Show segments, including "Rapper or Republican" until his final Daily Show appearance on December 13, 2012. In October 2009, he worked with rapper Slim Thug on the music video "Still a Boss", a parody of how the recession is affecting the rap community. Cenac costarred in Medicine for Melancholy, an independent drama by Barry Jenkins released in 2008 that includes issues of African American identity and gentrification in San Francisco.