The Mensheviks were the minority of the Social Democratic Party, the majority being the Bolsheviks under the authority of Lenin. While the Bolsheviks looked for the elite, the Mensheviks took a less elitist route, trying to attract the support of peasants and uneducated workers. They were trying to appeal to the lower classes, so why would they want a more dominating movement?
The first leader of the Mensheviks was Julius Martov. The Mensheviks were less disciplined and undereducated than the more powerful Bolsheviks. But they were more open and this attracted more supporters. In the Constituent Assembly the Mensheviks had far more delegates than the Bolsheviks. While the Bolsheviks had 248 delegates, the Menshevik had 822 delegates. But they did not get very many things done, this was more Lenin's area. While the Mensheviks were good philosopher it did not amount to anything getting done for change.
The Mensheviks believed that they needed a capitalist revolution to reach the level of socialism that they wanted. But Russia had not yet experienced industrialization and was not a capitalist nation. A capitalist nation is what Karl Marx said that they needed to achieve revolution. The Mensheviks also wanted a Parliamentary Bourgeoise that was led by capitalists, but capitalism was not necessary at the time.
The Mensheviks greatest weakness was that they allowed openness. This caused problems because this allowed many different opinions to be presented and conflicted against. They purely believed in the ideas of Karl Marx. While the Bolsheviks wanted to pull out of the war, the Mensheviks wanted to remain in the widely unpopular war. This caused a loss in support for the Mensheviks, causing the Bolsheviks to become increasingly popular with the working class. Many people even dropped from the Mensheviks to join the Bolsheviks. It was apparent that they were gaining less and less support, this led to the Bolsheviks seizing power and gaining control.