In 2004, Vietor turned down an offer from the John Kerry presidential campaign in favor of joining Illinois StateSenator Barack Obama for his first statewide run. His first job for Obama was driving the candidate's press van across rural Illinois. During this period, Vietor worked with and learned from Obama spokesman Robert Gibbs. Vietor was deputy press secretary for the Barack Obama Illinois Senate Campaign in 2004, then became deputy press secretary for Senator Obama the following year and press secretary the year after that. During Obama's presidential campaign from 2007–2008, he was Iowa Press Secretary. Following Obama's victory in the 2008 presidential election, Vietor became the Assistant White House Press Secretary, from January 2009 to January 2011; he then served as National Security Spokesman and Special Assistant to the President from January 2011 until March 2013. Vietor left the White House in March 2013, along with Obama's Director of Speechwriting Jon Favreau, to pursue a career in private sector consulting and screenwriting. Together, they founded the communications firm Fenway Strategies. In March 2016, Vietor became a regular co-host of The Ringer's political podcast Keepin' it 1600, along with Favreau and their fellow Obama administration alumni Dan Pfeiffer and Jon Lovett. Shortly after the November 2016 election, Vietor, Lovett and Favreau decided to pursue podcasting and activism on a full-time basis. They founded their own company, Crooked Media, and launched a new podcast, Pod Save America. In an interview with Recode's Kara Swisher, Vietor explained that "If Hillary had won, we probably would've kept doing this as a hobby... But when she lost, I think we all had this existential crisis, where it didn't feel right to wake upevery day and obsess about politics and what's happening in the country, and then go to work doing something else." Along with Ben Rhodes, who served as Deputy National Security Advisor under President Obama, Vietor also hosts a podcast covering global issues and policy making decisions called Pod Save the World. The podcast debuted on January 10, 2017. Vietor hosted a five-part miniseries about the Iowa caucuses called Pod Save America: On the Ground in Iowa. The miniseries was produced by Pineapple Street Studios.