Hartman's grandfather founded Hartman Oil Co. Before Hartman inherited the company, he gained experience working for the Derby Oil Company, Xerox Corporation, and Del Monte Foods. He purchased a controlling interest in Hartman Oil from his father in 1990. He opened restaurants in Wichita, El Dorado, Kansas and Lawrence, Kansas.
Hartman described alleged harassment by customers and locals, which were not verified by his employees. He associated the claimed acts with his candidacy as Kobach's running mate at his two Jimmy's Eggs Lawrence restaurants in which he said he had invested about $1.5 million. Hartman closed them suddenly without giving his employees any prior notice.[5] A manager who worked at both restaurants said she never witnessed any hostile acts, but staff at both locations had not expected them to succeed financially.[5] Hartman had also closed two Jimmy's Eggs restaurants in Wichita.[5]
In 2011, Hartman hired Michael O'Donnell, for a marketing job at which O'Donnell worked part-time, during the same year O'Donnell was running for Wichita City Council.[7]
In February 2017, Hartman declared his candidacy for Governor of Kansas in the 2018 election.[8] After loaning it $1.6 million,[9] he ended his gubernatorial campaign in February 2018, endorsing Kansas Secretary of StateKris Kobach.[10] The next month, Kobach selected Hartman as his Lieutenant Gubernatorial candidate.[11] The joint ticket of Kobach and Hartman was defeated by the Democratic ticket of state Senators Laura Kelly and Lynn Rogers, 48.0% to 43.0%, with the Independent ticket of Greg Orman and Republican state Senator John Doll, finishing third with 6.5%.[12][13]
In January 2019, Hartmann announced that he was "seriously considering entering the race" in 2020 for the open United States Senate seat to replace Pat Roberts but ultimately did not do so.[14]
