WASHINGTON - In returning $850,000 to donors associated with a disgraced fundraiser, Sen. Hillary Rodham Clinton sets a significant new standard for how campaigns should respond in the face of potential scandal. Clinton's decision also underscores the price — financial and political — that her campaign is paying for failing to spot trouble with the fundraiser, Norman Hsu, even after receiving a warning. The campaign announced it would now conduct background checks on its fundraisers, an extraordinary and potentially time consuming step. By returning the money, Clinton also puts pressure on presidential rivals and other politicians with rainmakers who have...