 Although some authors have claimed that the cleavages in Lipset and Rokkan's theory are still dominant for contemporary voting behaviors in Western Europe, others have argued that these traditional cleavages have become less important and new conflict lines have emerged.Conflicts that have emerged around several new political cleavages are for example cultural, such as conflicts over integration and multiculturalism, or environmental, such as ongoing politics over climate change.The cleavages in Lipset and Rokkan's classical theory have its origins in two developments in 19th century Western Europe.