alt Hacker NewsFor sure Fox et al. have been pushing the idea that scientists have biases, but it can also be true that science has become more biased.
Update: a little evidence. This doesn't cover change over time, but it strikes me as fairly extreme, unless you are willing to go very far down the "reality has a liberal bias" road: https://github.com/hughjonesd/academic-bias
Scientists can have biases, but science itself is just a methodology for determining truth. The political leanings of the people publishing papers shouldn't matter at all. Anybody can read a study and point out the problems with it. Anything else is just ad hominem.