> Seriously, over the years I've wracked my brain wondering why conservatism has moved so far to the radical fringe to the point where they simply seem to stand in opposition to even the most uncontroversial stances on things like global warming, healthcare, vaccines, basic human rights, etc.

Has conservatism "moved?" And if it has, has it moved to the right? If we were to time travel three generations ago, would the mainstream liberal culture then be more similar to the present day conservative culture or the present day liberal culture on the issues mentioned?

I submit that a present-day conservative would likely be a staunch liberal in those days. The Left has simply moved much further to the left.