James Gillett spent several years in public service, beginning with his admission to the Wisconsin Bar. He transitioned to California, where he held various positions, including Eureka City Attorney. Gillett was elected to the California State Senate and later to the U.S. House of Representatives. He was nominated by the Republican Party for Governor and subsequently elected, during which he signed significant legislation, including amendments to the Poison Act and the first eugenics law. After leaving public office, Gillett practiced law and lobbying in Washington, D.C., before retiring and later reopening his law practice.

James Gillett's political philosophy is marked by a calculated blend of progressive infrastructure initiatives and controversial social policies. His advocacy for expansive railroads and state highways reveals a focus on economic development, yet his support for stringent drug control and eugenics laws presents an ideological tension between modernization and social conservatism. Gillett's legislative actions, such as reforming parole guidelines while simultaneously endorsing eugenics, showcase an intriguing, non-standard approach to governance.