Right and left wing are always relative, not absolute. The Democrats might be right wing if transplanted with no changes to another country, but that doesn't matter. They are left win in comparison to the only other party that matters, so they are left wing.
It's always relative.
That's exactly how it works.
Left and Right are always relative positions, not absolute one. And they are relative not only to each other, but to the polics of the country as a whole.
Mount Everest's high IS absolute, so it's not a valid comparison.
Left and Right are, like what they are named for, merely directions. They mean nothing without a point to compare them too.
Right is typical the traditional position, orginally with the king, and left is the reform/change position.
Which is definitely true of right and left in the US.