A week after allegations of election fraud sent thousands of Russians into the streets chanting “Russia without Putin,” two prominent men have stepped forward to challenge Prime Minister Vladimir Putin in next year’s presidential election. Mikhail Prokhorov, a billionaire oligarch best known to Americans as the owner of the New Jersey Nets, and Alexsei Kudrin, a former finance minister who was fired after publicly clashing with President Dmirti Medvedev, have both announced their candidacies. Prokhorov, who said the decision to run was the most serious of his life, said he would offer his political platform in coming weeks. Steve Rosenberg, correspondent for the BBC, filed a report on efforts by Putin supports in Moscow to organize a rally. Ellen Barry, Moscow bureau chief for The New York Times, talks about the candidates and what this means for Russia.