Why is Scotland more left wing and England more right wing? Is there historical precedence for this? Has it always been the case? Just looking at recent election results and it seems the majority of England overwhelmingly vote for right wing and center-right parties while most of Scotland seems to vote for left wing or center-left parties.

It seems obvious to me why the two countries would want to separate and have their own independence as their cultures and political values seem very different. But has this always been the case or has something changed that?