Also the fact that there is no competing ideology. Conservatism is just progressivism 20 years ago.

In theory, it is a competing belief system, namely "stick with what works" and the wisdom of the ages. Unfortunately, the right has a tendency to accept the status quo even if it does not work.

If you want a vacuous ideology, it's progressivism. They're the mirror image of conservatism: where conservatives want things to stay the same, they want "change" - even change for the worse. The only thing that has been constant since the beginning of progressivism is that it accepts ideas that have novelty. That's it.