A sacred cow is an idea, custom, or institution held, especially unreasonably, to be above criticism...a taboo. Essentialy something that people do not like to question.

Regardless of your political leanings, we are in an environment where it seems a lot of sacred cows are up for grabs.

NAFTA

Paris Agreements

NATO

Foreign trade

Government adminstration

Political correctness

Truth

It can be unsettling or not depending on your point of view. Are there others?