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 the Teamsters Local 688, where one of his chief responsibilities was advising union members nearing retirement on their personal finances.

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 Mayor Charles Wheeler.

He worked with a national bipartisan coalition of state and local treasurers and comptrollers to set clearer guardrails around investing public funds.

He joined his counterparts around the country to call on the U.S. Securities and Exchange Commission to establish consistent standards around fees and expenses associated with private equity for public funds.

The proposal represented the largest commitment to affordable housing in Missouri's history, including for thousands of veterans, school-age children and those suffering from mental health issues.

Through his effective stewardship of the program he was able to secure an additional $400 million in lending power  during his time in office to bolster small businesses around the state.

Zweifel oversaw MOST, Missouri's 529 college savings program, and lowered fees by as much as 80 percent during his time in office, cutting costs for savers and making higher education more accessible for thousands.