Where did the practice of using quotation marks to discredit an opponent ("scare-quotes") come from?

This is a practice extremely prevalent on conspiracy theory blogs and social media (a.k.a., conspiracy theory blogs), but where did the concept of discrediting opponents with quotation marks come from?

The quotation marks are often put around the nouns referring to one's opponent, or sometimes to parts of their view.

For example:

According to "scientists", vaccinations are the number one way to prevent disease, however...

or

This guy I hate "knows" that that thing I hate is such and such...

I've now learned that this tactic is referred to as "scare-quotes". My question isn't about the origin of the phrase "scare-quotes" (this question), but rather, when did the tactic of using scare-quotes become a common practice?

Solution 1:

Very similar to what you describe for written text is the use of air quotes when speaking. In my opinion, as air quotes mimic the typographic symbol of quotation marks, the ironic or discrediting use of quotation marks has to have come into play before air quotes did.

This site is able to date back the use of air quotes to 1927.

Of course one could argue there is a difference between ironic quotes and scare-quotes, but I believe they are closely related, as the act of "marking something as possibly ironic" is a nice method to have the discrediting quote sound a little less offensive.

Solution 2:

Scare quotes are often used in the same contexts where you might use the phrase so-called to indicate skepticism or sarcasm. It seems likely to me that this notation is a form of abbreviation of this, they both refer to the literal name that someone or something is called by.

For more about so-called, see

Does "so called" have a negative connotation in English?

What is the difference between "alleged" and "so-called"?