Activists in the Communist Party (Opposition) played a role in a number of trade union organizations of the 1930s, particularly in the automobile and garment industries.

A growing disaffection with the Soviet Union in the years after the Great Purge of 1937–38 ultimately led the group to drop the word "Communist" from its name before its dissolution in the first days of 1941.

A so-called Left Opposition centered around James P. Cannon, Max Shachtman and others, supported Leon Trotsky and were expelled in 1928 to form the Communist League of America.

[2] The organization declared that: Under the pretext of 'fighting the Rights,' the present leadership of the Communist International has been revising the fundamental principles of Leninism and distorting and destroying the Leninist line of the Comintern.

As a result the sections of the Comintern have been thrown into isolation, chaos, and confusion, and the best and most experienced revolutionists driven out and expelled to be replaced by incapable politically bankrupt 'new leaderships.'

[3] The new "Communist Party (Majority Group)" demanded that the official CPUSA turn away from the "opportunist sectarian" perspective of the Third Period and its use of "ultra-left phrases in the leading campaigns of the party", cease with its mass expulsions of dissidents and immediately reinstate those recently expelled, and "examine and take a stand" against the decisions of the 10th Plenum of the Executive Committee of the Communist International which represented a revision of the decisions of the 6th World Congress of the Comintern.

During its first years, the CP(MG) considered itself a "loyal opposition" to the official Communist Party, a fact reflected by the group's decision to endorse the Congressional and State candidates of the CPUSA in the 1930 elections.

On April 3, 1932, Rivera lectured under the auspices of the Communist Party (Opposition) on "Trends in Modern Art", with his friend Bert Wolfe handling the task of translation.

"[6] Despite being subjected to such violence, the Lovestoneites nevertheless once again endorsed the electoral ticket of the official Communist Party in the election of 1932, declaring the Republicans and Democrats "stand for this cursed system", while the Socialists "frequently support the conservative union leaders who are doing their best to paralyze the struggles of the workers and to hand them over to the tender mercies of the bosses.

Representatives of the CP(MG) collaborated with their comparable others in Germany, Sweden, and Czechoslovakia in a preliminary gathering held in Berlin in March 1930 to organize the event.

Early in February 1933 former National Secretary Ben Gitlow submitted his resignation from the Lovestone organization, having come to see the general line of mass collectivization and frenetic industrialization in the USSR as "basically wrong" with the matter a "decisive question of fundamental principle.

"[18] Benjamin Gitlow, an early Secretary of the organization who later broke with communism, declared in his 1940 memoir that "the Lovestonites did not attain a membership in excess of three hundred and fifty throughout my connection with the group.

[20] In the view of the leading scholar of the ILLA and its predecessors, the historian Robert J. Alexander, "Will Herberg's estimate of Lovestoneite membership would seem nearer the facts than that of Gitlow.

"[21] The Lovestoneites had as many as nine functioning branches in New York City over the course of the organization, as well as other branches in Austin, Texas, Philadelphia, Wilkes Barre, Fredericktown-Millsboro, Pennsylvania, Pittsburgh, Fort Wayne and Kokomo, Indiana, Chicago, Cleveland, Detroit, Lansing, Muskegon, Pontiac, St. Louis, Boston, New Bedford, Hartford, San Antonio, Los Angeles, Troy, New York, Baltimore, Passaic, New Jersey, Fall River, Massachusetts, and Buffalo.

[25] Instructors included Jay Lovestone, Ben Gitlow, Charles "Sasha" Zimmerman, Will Herberg, Bert Miller, Herbert Zam, and others in addition to Wolfe and Benjamin.

[25] The Marx-Lenin School held a public lecture on Sunday afternoons and conducted its courses during the evening hours, Monday through Thursday.

Other course titles included, "Fundamentals of Communism", "Program of the Communist International", "Marxian Philosophy", "Social Forces in American History", and "English for Foreign-Born Workers.

Courses cost $2.50 per class, with tickets to the headlining presentations by Jay Lovestone available on a single admission basis for 25 cents.

[31] Unsurprisingly, enormous controversy began to flare up, with the New York World-Telegram opining with an April 24, 1933 banner: "RIVERA PAINTS SCENES OF COMMUNIST ACTIVITY AND JOHN D. JR. FOOTS BILL.".

[31] Nelson A. Rockefeller was quick to quash the controversy by pulling the plug on the almost-completed work, paying off Rivera and immediately covering the massive mural before destroying it early in 1934.

He chose the location of the Lovestoneites' New Workers School on West 14th Street, putting up movable walls in the rented building and creating the mural with his assistants at his own expense.

The party's Harlem branch, in which Edward Welsh played a key role, additionally published a mimeographed sheet, Negro Voice from 1935 to 1936.

[39] In 1937 Mortimer and Bob Travis led a series of successful sit-down strikes, first at General Motors and then at Chrysler, Hudson, Packard and Studebaker.

In the first week of September Lewis sent a CIO commission consisting of Philip Murray and Sidney Hillman to offer Martin an ultimatum: either re-instate the ousted board or be expelled from the Congress of Industrial Organizations.

[47] In January 1936, Julius Herskowitz, a Lovestoneite unionist trying to organize a plant that made Mickey Mouse dolls was beaten by an unknown assailant and his skull was fractured.

In September the dissident elements, not all Lovestoneites, met in convention and constituted themselves the Progressive Group within the UMW and resolved to try to get reinstated in the official organization.

The opposition coalition did not last however, as the other leaders called for the creation of a new union in August 1933 and other disaffected members gravitated towards the Progressive Miners of America.

In this instance the Communist-led Rank & File group withdrew their candidate so that Sam Freedman would stand against the supposedly Mafia-backed Bob Kellman.

While in control of the union they faced considerable opposition from the Communist ex-TUUL faction, who tried to have the entire executive board recalled at the group's October 1934 convention.

Lovestoneite Eli Keller was manager of the AFSW local in Paterson, New Jersey until 1935 when he resigned because of "irresponsible" behavior on the part of the executive committee.