Many believe that President Bush's decision to withhold federal funding for embryonic stem cell research was vindicated when new breakthroughs were made in adult and pluripotent stem cell research. Research on adult stem cells has proved more effective and less controversial since it does not involve the destruction of human embryos.
President Bush signed an executive order on August 9, 2001 that banned the use of federal funds for embryonic stem cell research with the exception of existing embryos. In other words no new embryos could be created for destruction.