After graduating from Yale Law School, Tanden moved to Washington, DC, where she has worked on domestic policy on Capitol Hill, in think tanks, and for senatorial and Democratic presidential campaigns. She has also written on Indian-American issues.[3]

She worked with President Bill Clinton's campaign on new energy policies and health-care reform. Continuing her association with the Clintons, Tanden was policy director for the 2008 Hillary Clinton campaign, shaping its policy proposals.[4][3] After Barack Obama was nominated as the Democratic presidential candidate, Tanden served as his domestic policy director for his campaign.[3] She also served in his administration as senior adviser to Secretary Kathleen Sebelius of the Department of Health and Human Services, aiding the effort to gain passage of Obama's healthcare legislation.[5]

In 2011, Tanden was selected as President of the Center for American Progress, a Washington Democratic think tank. She had started with the group soon after its founding as Senior Vice President for Domestic Policy, also serving as Senior Vice President for Academic Affairs and, starting in 2010, as Chief Operating Officer.[5][6]

Tanden has had a regular column for The New Republic online. She has appeared on the NewsHour with Jim Lehrer, Real Time with Bill Maher, MSNBC, CNN, and Fox programs.[5]

In 2016, WikiLeaks released thousands of private, stolen emails in a data dump which came to be known as the Podesta emails. In one exchange, on August 11, 2015, between Tanden and John Podesta, while discussing news that Lawrence Lessig was exploring a bid for the Democratic nomination, she said of Lessig, "I fucking hate that guy." In turn, Lessig responded that while he supported whistle blowing and the pardon of Edward Snowden, Tanden should not have to be burdened with having her private emails scrutinized and that it was not in the public interest.[7] Tanden called the release of her personal communications, which often feature her blunt private assessments, a painful experience to endure.[8]