As the vanguard of the working class, the Communist Party represented power and control. Whereas the overwhelming majority of workers belonged to trade unions, a smaller number joined the party. The trade unions accepted almost all applicants; the party was more selective. Although Ukrainians never controlled the leading positions in the KP(b)U during the 1920s and early 1930s, they did become the majority of the party's rank and file. This radical increase was significant. Since the party represented political authority, its demographic and cultural Ukrainianization was an important indicator of the party's seriousness in legitimizing itself in the non-Russian regions.

The KP(b)U, the largest non-Russian regional party, was one of the main components of the VKP(b). The Ukrainian party expanded from 54,818 members and candidate-members in 1922 to 550,443 on January 1, 1933, comprising 13.6 to 17.0 percent of the entire membership of the VKP(b). In addition to its size, the party's social composition contributed to its importance. By attracting large numbers of miners and metallists from the Donbass, Dnipropetrovs'ke, Kharkov, Nikolaev, Kryvyi Rih, and other cities in the Ukraine into its ranks, the Communist Party of the Ukraine in the 1920s possessed a higher percentage of members of working-class background than even in the RSFSR.

Significantly, more Ukrainians joined the party than any other non-Russian group. They made impressive strides within the party membership of the republic – from 11,920, or 23.3 percent of the KP(b)U in 1922, to over 300,000, or 60.0 percent by October 1933. This influx transformed an overwhelmingly Russian organization into one more representative of the national composition of the Ukraine (see Appendix 14).