Inspired by Ross Perot's 1992 presidential campaign, he first ran for Congress as an independent in that year's election in Minnesota's 6th congressional district, but lost.

[3] During his university years, Barkley volunteered for George McGovern's 1972 presidential campaign because of his opposition to the Vietnam War.

On November 4, 2002, Ventura appointed Barkley to complete the Senate term of Paul Wellstone, who died in a plane crash on October 25.

Barkley served until the 107th United States Congress ended on January 3, 2003, when he was replaced by Coleman, who won the election.

During his weeks as senator, Barkley helped pass legislation establishing a memorial for Wellstone and provided a pivotal vote in clearing the final passage of the Homeland Security Act.

[5] After leaving office, Barkley did a stint in St. Paul as a state government lobbyist for a tobacco company, a casino, and the private prison industry.

[4] Beginning in April 2005, Barkley served as director and chief strategist for Texas independent Kinky Friedman's 2006 gubernatorial campaign.

[17][18] Barkley ran against Minnesota Supreme Court Associate Justice G. Barry Anderson in the 2012 election.

[20] He later focused on estate planning law and continues to advise unaffiliated political candidates, such as Kinky Friedman's Texas gubernatorial campaign.