Qualified Immunity shields government officials from being sued for discretionary actions performed within their official capacity. What this says is that ignorance of the law is no protection for you as a civilian (Ignorantia juris non excusat), but that legislators and cops (those with power and guns) can make these mistakes and have limited immunity from prosecution or lawsuit (consequences) as long as their mistakes are "reasonable." This has been widely supported by Democrats and Police Unions, the Bar, and other leftist organizations (collectivists, authoritarians), and generally opposed by Libertarians and many conservatives (individualists).
Two Supreme Court rulings support this abuse of power protection:
- 1982: Harlow v. Fitzgerald  the court decided that public servants enjoy "qualified immunity," which means that they cannot be held civilly liable for violating a person's rights unless the person's right is established "beyond dispute," and the officer violates a clearly established law that a "reasonable" officer should know. A far higher bar than civilians have in following the law.
- 2014: Heien v. North Carolina  An 8-1 decision that the police needn't actually know the law – that they can enforce a mistaken understanding of the law, again, as long as their mistakes are "reasonable." So, in a colossal twist of irony, the people charged with enforcing the law are not required to know what the law is and may even use ignorance of the law as a defense.