MOSCOW — Ksenia A. Sobchak, a socialite and popular journalist turned Russian presidential candidate, opened her campaign on Tuesday by calling elections in Russia “a very expensive show of a very low quality” but justifying her participation as the only way to change the country’s corrupt political system.

“I think we should be fighting even in these dishonest conditions,” Ms. Sobchak told a packed news conference at the Stanislavsky Electrotheatre in central Moscow. “My task is to turn it upside down and install my own rules of the game.”

Ms. Sobchak promised to use her “loud voice” and widespread popularity to fight indifference and apathy among the underrepresented slices of the Russian society, and couched her candidacy in generational terms.

“Perhaps we won’t win this election, but I am confident that today we can lay a foundation that will in a few years lead my generation into power,” Ms. Sobchak, 35, said. “Our generation will define its own life.”