Leon Trotsky is expelled from the Soviet Communist Party, leaving Joseph Stalin in undisputed control of the Soviet Union.

Leon Trotsky’s expulsion from the Soviet Communist Party in 1927 marked a decisive turning point in Soviet political history and symbolized the final victory of Joseph Stalin’s faction over the opposition. Trotsky, once one of the key architects of the Bolshevik Revolution and the Red Army’s founder, had long been at odds with Stalin’s growing control of the Communist Party. By the mid-1920s, their ideological differences had solidified—Trotsky championed “permanent revolution,” emphasizing the need for global socialist movements, while Stalin promoted “socialism in one country,” focusing on consolidating socialism within the USSR first.

The internal conflict intensified as Trotsky and his supporters, known as the Left Opposition, criticized the increasing bureaucratization of the Soviet state and the suppression of inner-party democracy. They accused Stalin and his allies of betraying Lenin’s revolutionary ideals by creating an authoritarian regime that prioritized political loyalty over ideological purity. In response, Stalin used his control over the party apparatus to isolate Trotsky, removing him from key posts and undermining his influence among the rank-and-file members.

By late 1927, Trotsky’s defiance reached its peak when he and other opposition figures attempted to rally support during the tenth anniversary of the October Revolution. The government swiftly cracked down on these efforts, accusing the opposition of factionalism and anti-party activities—charges that carried severe consequences in the Stalinist political climate. On November 14, 1927, Trotsky and Grigory Zinoviev were expelled from the Communist Party, marking the formal end of organized resistance to Stalin’s rule within the party.

Following his expulsion, Trotsky was first exiled internally to Alma-Ata in Kazakhstan and later deported from the Soviet Union altogether in 1929. Despite his removal, he continued to write and critique Stalin’s regime from abroad, warning of the dangers of totalitarianism and the distortion of Marxist principles. His expulsion not only solidified Stalin’s dominance over Soviet politics but also symbolized the suppression of dissent that would characterize much of Soviet governance in the years to come.