That’s a new one (the bit about MLK being a Sanger stooge, I mean). I know her plans to have black pastors promote it, and I also know about Jesse Jackson basically selling out his pro life views for Democrat votes, but I don’t recall MLK doing that (and I know a guy who thinks MLK is vastly overrated, and even HE doubted MLK supported Sanger and abortion before his death, though he did say he probably would have supported it had he lived long enough). And quite frankly, considering his niece is Aleida Scott King, one of the biggest pro-Life advocates out there, and she indicated that MLK would have approved of her actions for the pro-Life movement, I find it extremely unlikely he would have supported Margaret Sanger, or Planned Parenthood.
Aleida is the black sheep of the King family. The rest are Dems and very pro abortion as was he. Google King and Sanger.
https://www.plannedparenthood.org/planned-parenthood-gulf-coast/mlk-acceptance-speech