Science is the search for knowledge through observation, experimentation, and systematic study. Much of it relies on funding, which can sadly include political funding. We should all be aware of the unwanted side-effects of political funding, mainly the establishment of a political agenda. So 1+1=2 and in order to prevent political bias in science we would have to forbid political funding for scientific studies and experiments. Maybe it's not that simple, I'm sure there may be other factors involved, but it's a start.