I've only heard of the Red Pill in reference to the Matrix. Does it have that idea from "The Prince"?

The Prince is the basic concept of red-pilling. I.e. take the red pill and be exposed to the realities of the world where nice guys finish last.

No literal red-pill as in the Matrix but the ideas that mainstream "red-pilling" espouses are those of The Prince.

No, The Prince is very literal.

Inspiration for the red pill (which represents choosing knowledge, however ugly, over pleasant ignorance) would be more like... the apple in the Garden of Eden. Or the Allegory of the Cave maybe. Or Alice in Wonderland (which Morpheus directly mentions in the Matrix)

Redpillers latched onto that red pill imagery because they view themselves as, you know, having the best grasp on reality. Unlike the poor ignorant masses. Or so they believe.

"Redpilled" views do have some things in common with Realpolitik, and The Prince, in the sense that they're kind of nakedly amoral and rather ugly.

I think the red pill is a direct reference to the matrix. Its kind of weird they have such degratory views on sex and gender, given the directors of their favorite movie they cant stop talking about.

For sure, the red pill is a direct reference to the Matrix. I think previous poster was asking if the Matrix took that idea from somewhere.

    Its kind of weird they have such degratory views on sex and 
    gender, given the directors of their favorite movie they 
    cant stop talking about.
Yeah. I think the connection they see is that the reality Neo chose to confront (a humankind enslaved by machines) was unpleasant, and the redpill gang knows their version of reality is very ugly as well.