Sonia Gandhi - considered India's most powerful politician - on Friday celebrated her 10th year as chief of the ruling Congress party, surrounded by supporters crying, “Long live Sonia.” Italian-born Gandhi, who came to India as a shy bride in her early 20s to emerge as political kingmaker, marked the anniversary at her sprawling bungalow in the heart of the capital. Prime Minister Manmohan Singh, a quiet economist vaulted to power when Gandhi refused the premier's job after leading Congress to an upset win in the 2004 elections, led the congratulations. However, political pundits are unsure whether Gandhi will take Congress to victory again following a string of setbacks for the party in state polls. “She has positioned it better through making alliances... but whether she can carry it forward is still unclear,” said analyst Mahesh Rangarajan. Gandhi, named by Forbes Magazine in 2007 as the world's sixth most powerful woman, has “managed to retain power without acquiring the burden of office,” said Prabhu Chawla, editor of news magazine Indian Today. Gandhi, a youthful 61 whose dark brown hair only now shows streaks of grey, took over the party's reins when it faced “drift and despondency,” s aid Foreign Minister Pranab Mukherjee, one of her many well-wishers. Sonia, who has held the Congress chief's job for the longest time in the party's 122-year history, was thrust into the limelight after her husband, former premier Rajiv Gandhi, was killed by a suicide bomber in 1991. Her son Rahul, whom she is regarded as grooming for the prime minister's job, was also on hand as party workers danced to drums and distributed sweets. __