Physics is a branch of the natural sciences that uses empirical experimentation and well-defined first principles to create mathematical models of the natural world that can accurately predict the behavior of a physical system. Its methodology can be and has been applied to virtually any area of study, from sociology to formal logic theory, and because results from physics have been extremely accurate in predicting the behavior of many physical systems, the mention of this field has been avoided almost universally in politics as it puts a very high standard of truthfulness on everything around it.
While physicists can be of various political and religious persuasions, they don't like things that distort truth, or especially things that distort truthful discourse. As such, most physicists disliked the Bush administration due to their willful ignorancification when presented with such truths as Global warming, the promise of embryonic Stem cell research, the fundamental importance of Evolutionary theory, and various social statistical analyses demonstrating the lack of effectiveness of programs such as abstinence-only education and standards of the No Child Left Behind Act.
Physics has been the driving force of revolutionary technological development for the past two centuries. Therefore, people whose brains are only able to cycle thoughts slower than a nanoHertz tend to feel that technology advances "Too dab-durn fast!" and are intimidated by scientists, particularly those in this field. If they choose to pursue the matter further, they inevitably decide that professors are "too liberal", that the government shouldn't fund "research that isn't useful", or that there is a massive conspiracy in physics to pretend they're God and make miniature universes that eat up our universe and destroy everything. Even though the last part is true, it's quite an unfounded assumption for anyone who has not yet even gone through ritualistic bloodletting at the shrine to Ahura Mazda, which is part of the application process at the Large Hadron Collider.
Conservatives and physics
Conservatives like to invoke the importance of physics research when they talk about doing things like putting a man on Mars, making American math and science education competitive with the rest of the world, or making a big bomb with little bombs inside so when it explodes it shoots bombs at you. Then they liked to bash it when they cut NSF funding and tried to remove Evolution and the Big Bang from science curricula. Liberals should be careful not to make a similar fallacy by asserting that scientific research can solve most of the world's problems, while failing to realize that another mass extinction would do the same thing much more quickly.