Maxim Shemetov/Reuters After a campaign without any serious political challengers, Russian President Vladimir Putin has been re-elected president of Russia for a fourth term. He will serve for at least another six years. Behind Putin, a Communist Party challenger took second place, a nationalist took third, and anti-Putin liberal and socialite Ksenia Sobchak took fourth. Experts say the longer Putin stays in power in Russia the more difficult it will be for him to hand off the reigns to a successor. KEMEROVO, Russia (Reuters) - Russian President Vladimir Putin won a landslide re-election victory on Sunday, extending his rule over the world's largest country for another six years at a time when his ties with the West are on a hostile trajectory. Putin's thumping victory will extend his total time in office to nearly a quarter of a century, until 2024, by which time he will be 71.