Science is under assault from both ends of the political spectrum in the form of budget cuts and an increased mistrust of scientists' motives. The title of Vannevar Bush's seminal report “Science: The Endless Frontier” has taken on new meaning as federal science agencies have experienced the frontier justice of steep budget cuts or even elimination. The Bush report, which was published 50 years ago, is the blueprint for U.S. government support of scientific research and development since World War II. Crediting scientific and technological breakthroughs with helping to win the war, Bush portrayed research and development as an engine for promoting national security and prosperity. The national security aspect has not been seriously questioned, but the role of nondefense science is being drastically redrawn by the 104th Congress over President Clinton's protests. At the same time, scientists are facing challenges from partisan politics on the left as environmental groups take confrontational stances toward scientific research, often due to poor communication. Unless these challenges are met, science could lose its unique role as a source of objective information.