A member of the Communist Party USA from about 1932, Mortimer was a critic of the efforts of the conservative American Federation of Labor to control the union and was a leader of a so-called "Unity Caucus" which led the UAW to join forces with the more aggressive Congress of Industrial Organizations (CIO).
In the spring of 1941, Mortimer's refusal to follow the anti-strike line of the UAW's governing Executive Board during a highly controversial work stoppage at a California aircraft factory lead to his termination by the union and effectively brought an end to his career.
[1] He later recalled that one of his earliest memories of life as a young boy in Central Pennsylvania involved "walking behind parades of striking miners.
[3] After leaving the coal mines, Mortimer worked as a rail-straightener in the steel mills of Lorain, Ohio, a brakeman on the Pennsylvania and New York Central Railroads, and a conductor for the Cleveland Railway Company.
[3] This industrial job-hopping culminated in 1917 when Mortimer was hired as a drill operator at the White Motor Company of Cleveland, Ohio, then a leading manufacturer of trucks and busses.
[4] The AF of L organizer for the Cleveland district, George McKinnon, appointed conservative trade unionists to head the new local, thereby excluding Mortimer from high office.
[4] Mortimer did, however, manage to maintain a high profile and effective direction of the local's tone and agenda as the head of the Grievance Committee of the new organization.
[4] In this capacity, Mortimer was instrumental in orchestrating weekend job stoppages until the company relented and agreed to pay time-and-a-half for Saturday and Sunday work.
"[6]Mortimer and other Michigan Communists active in the trade union movement took pains to maintain discretion in this period, going so far as to hold their unit meetings in the middle of the night, the time and location of which was kept a carefully guarded secret.
[7] This mania for secrecy served to inhibit CPUSA activists from placing the question of socialism before their fellow trade unionists, effectively stifling their self-proclaimed task of radicalizing the working class from the outset.
[7] At the 1936 annual convention of the United Automobile, Aircraft and Agricultural Implement Workers of America (UAW) Mortimer headed a successful drive to unseat Frances Dillon as President of the union.
[8] An additional unintended consequence soon became clear, as the attack by Martin and Lovestone essentially created a grand alliance of liberal and radical unionists which would soon take the UAW out of the AF of L and into the fledgling Congress of Industrial Organizations through a so-called "Unity Caucus.
[13] With World War II already raging in Europe, a strike at an aircraft plant in which the most famous Communist was playing a role was seen as a positive threat to national security.
[14] The tense situation was repeated in 1941 when Mortimer played a leading role in a strike against the North American Aviation plant located in Inglewood, California.