It is strictly a generalisation in terms of attitude, rather than a concrete political doctrine.
The simple fact is, human beings of any political persuasion rarely use power to give themselves less of anything, including a proportionately increasing belief that they are correct, and anyone who disagrees is, at best, someone to be ignored, and at worst, someone to be elminiated.
Margaret Thatcher was famously renowned for her ability to comprehend opposition, but not dissent. Fortunately, we don't do 'disappearing' of people with whom the government does not agree ... yet.