I suggest Will Mayer google "Racist and Eugenicist statements by Margaret Sanger". The source of each statement is cited. Sanger was an evil, hateful progressive.  I'm sure she disagreed with the KKK as they were too visible.  Her racism and hatred was much more underhanded.  "Planned Parenthood" was founded to purify the "race".  She, like all progressives, wanted an all white utopian society, with, of course, themselves in charge.  There's a reason Hitler & the nazis borrowed many of their ideas.  They both had the same ideology.  And despite decades of propaganda to the contrary...nazis were every bit as left wing as any other white supremacists left wing group.
She may be a saint to the left...but she's surely burning in hell as we speak!