The top Democratic candidates for the US presidency are supporting a congressional move to label China a currency manipulator, Reuters reported. Senators Barack Obama and Hillary Clinton signed on as co-sponsors of a June 13 bill by Senate Finance Committee chairman Max Baucus and ranking Republican Charles Grassley. The bill, which calls for swifter action against countries labeled as currency manipulators, is primarily aimed at China. "China has manipulated its currency for years in order to gain an unfair advantage over the United States in trade," Obama wrote in a letter to Treasury Secretary Henry Paulson last month. Clinton said in a speech last month: "We should neither fear a stronger China nor ignore it. That means engagement and understanding, but also frank dialog on issues ranging from trade to currency manipulation to human rights abuses and the environment."