In the 1980s, Jarding served as Executive Director of the South Dakota Democratic Party, and on the first Senate campaign of former Senate Majority Leader Tom Daschle. In 1988 and again in 1994 he worked on the successful U.S. Senate campaigns of Bob Kerrey of Nebraska. He also worked as national Communications Director on Kerrey's unsuccessful 1992 presidential campaign. In the mid-1990s, he served as Communication Director and later a senior advisor for the Democratic Senatorial Campaign Committee (DSCC). Jarding also ran Leadership PACs for Kerrey and U.S. Senator John Edwards of North Carolina.
In 2001, Jarding managed Mark Warner’s victorious Virginia gubernatorial race. This race was featured heavily in a profile of Jarding by Matt Bai that ran in the New York Times Magazine in 2002.
In 2006, Jarding was a senior adviser to the winning Virginia U.S. Senate campaign of former Secretary of the Navy, Jim Webb, who defeated the incumbent Republican senator George Allen.
In 2008, Jarding was the campaign manager on the winning campaign of South Dakota U.S. Senator Tim Johnson who was the number one target for defeat that year by the National Republican Senatorial Committee. Johnson won that race with over 60 percent of the vote.
In 2011, Jarding was a founding partner in the international political consulting firm, SJB Strategies International. He has since worked on campaigns and causes with clients in Asia, Africa, South America and Europe.
In 2012, Jarding was the recipient of the George McGovern Grassroots Award, named after the 1972 Democratic Presidential nominee and international statesman, George McGovern, for his work to "substantially improve" the South Dakota Democratic Party. In 2013, Jarding was named a member of the Selection Committee for the Goldsmith Prize for Investigative Reporting for 2012-2013 at Harvard University.