Pew Research has determined that the Overton window has barely moved at all for the right-wing, but has moved quite a bit for the left-wing. This means that what you perceive as nudging may in fact just be trying to hold it in place. We can call it a Theory of Overton Relativity.

https://imgur.com/QJd2gRB (a really interesting set of histograms)

https://www.pewresearch.org/fact-tank/2017/10/05/takeaways-o...