Politicians have made the debate over embryonic stem cell research unnecessarily emotional and have impacted scientific research. According to some experts, many politicians use the issue to stir up unnecessary emotion on both sides of the issue. For example, when President Bush vetoed the Stem Cell Research Enhancement Act of 2007, he stated that the federal government should not support "the taking of innocent human life through stem cell research ("Examining the ethics"}. Statements like this have impacted researchers in a way that hinders scientific progress. In one such instance, leading biology professor Roger Pedersen left his position at the University of California San Francisco in response to the Bush administration's actions (Abate). In cases such as Pedersen's, federal funding of research is a central concern. However, some experts caution that scientists should not make decisions based on political and emotional rhetoric. Henry James, a head researcher at Johns Hopkins, explained that "politicians don't know science," so scientists should not let politicians guide their research. both synthesis and analysis synthesis analysis neither synthesis nor analysis