Five years ago, the Bush administration decided to severely limit federal financing for embryonic stem cell research, a move that set off vigorous competition among the states to provide support for a research field that many scientists say could bring about major medical advances. New Jersey was first out of the gate, pledging millions of dollars for stem cell research in the state. California raised the stakes with a huge $3 billion bond initiative, and other states followed with ballot initiatives or legislation to give scientists grants or to build research centers. Those efforts, supporters promised, would also bring in new jobs and tax revenue....