Conservatism is resisting change, so the whole purpose of a conservative party is to resist progressive forces, provide resistance to the rapid and sometimes over reactive changes that can result from unchecked progressivism. A good example of where it went off the rails is the Chinese cultural revolution. Conservative voices were silenced, even killed by the thousands. Years of history and artifacts were destroyed along with the economy itself. There needs to be someone to speak up when things are going crazy, and a shift to the right can be a sign that things went too far.