You can either make the argument that "it is sinister now, but it was great before" or you can try to make the case that "progressivism has always been sinister". But you are going to have to prove your case either way.
I choose to hit the foundation, because it's always been sinister.
“But you are going to have to prove your case either way.”
I propose an alternate strategy. I tell people that DemocRATS HATE America. When they ask how you can say that I point out that the RATS criticize EVERYTHING about America starting from the voyage of Columbus to the present day. They will push back but you have planted a seed in their mind. Eventually they see it.