Each of the leading presidential contenders has done favors for campaign contributors, often compromising the environment in the process, according to a new report conducted by the Center for Public Integrity. Bill Bradley has drawn hefty campaign contributions from the chemical industry and introduced numerous bills that eliminate tariffs on certain highly toxic pesticides, the report asserts. George W. Bush, who has gotten big cash infusions from the oil and gas industry, let major corporations such as Exxon and Marathon Oil craft their own emissions regulations, the center says. John McCain “rarely breaks ranks with the special interests who finance his campaigns,” including mining companies and real estate developers. And the report accuses Al Gore of supporting a 1997 government sell-off of a 47,000-acre oil field that benefited Occidental Petroleum, a company with decades-long ties to the Gore family.