Zweifel was born in St. Louis, Missouri, and grew up in the surrounding communities of St. Louis County, Missouri, attending grade school in Florissant and Hazelwood West High School in Hazelwood. The first member of his family to attend and graduate from college, he earned both a bachelor of arts degree in political science and an MBA from the University of Missouri-St. Louis. Prior to running for public office, Zweifel was the research and education director for Teamsters Local 688, where one of his chief responsibilities was advising members nearing retirement on their personal finances. Eisenhower Fellowships selected Zweifel as a USA Eisenhower Fellow in 2009.
Family
His wife, Janice, owns a business in St. Louis They are the parents of two adopted daughters, Selma and Ellie.
Political career
Zweifel represented the 78th District in the Missouri House of Representatives. He first won election to the House of Representatives in 2002 by a 67-vote margin and earned the distinction of being the only Democrat in the state to defeat a Republican incumbent in that election year. While in the House, Zweifel served three terms and led Democratic policy strategy and developed solutions to help Missouri families, developing proposals on early childhood education, helping seniors cope with property taxes, and guarding citizen privacy. He was the ranking member on the Ways and Means Committee and the Special Committee on Tax Reform. He also served on the Special Committee on Retirement, the Joint Committee on Tax Policy, and the Special Committee on State Parks and Waterways. He chaired the Missouri HouseDemocratic Campaign Committee during the 2006 election cycle, leading all Missouri House candidate recruitment and fundraising efforts. The effort resulted in the largest Democratic net gain in the House since the 1978 elections. In the 2008 election cycle, Zweifel won the Democratic primary for state treasurer, topping a four-candidate field which included 2004 nominee and Arnold, Missouri Mayor Mark Powell, former state Department of Economic Development official Andria Danine Simckes and former Kansas City MayorCharles Wheeler. He went on to defeat Republican State Senator Brad Lager in the general election. He is the youngest person elected to that office in over a century, celebrating his 35th birthday the day before he was elected. Zweifel was re-elected in 2012, defeating Republican Cole McNary and Libertarian Sean O'Toole. Zweifel was ineligible to seek reelection as state treasurer in 2016, and announced that he would not run for any other political office that year.
