On June 10, 1937, President Franklin D. Roosevelt nominated LeBaron to a seat on the newly established first circuit court of Hawaii.[3] On March 2, 1942, Roosevelt elevated LeBaron to the Territorial Supreme Court,[4] to the seat vacated by the elevation of Samuel B. Kemp to the position of chief justice.[5]
In 1955, President Dwight D. Eisenhower declined to renominate LeBaron, a Democrat, to another term on the court, instead appointing Republican Circuit Court judge Philip L. Rice to the seat, prompting criticism from Associate Justice Ingram Stainback.[6] Stainback also deemed it "cruel" that LeBaron was "let out without any trouble or compensation", though Rice expressed appreciation of LeBaron's courteous response to the situation.[7] In 1957, LeBaron "set off a controversy" when he alleged in an annual review of the Bishop Estate that the practice of the Kamehameha Schools giving preference to the admission of students of part-Hawaiian ancestry constituted racial discrimination and unlawful segregation.[2]