Isn't "progressive" like the word "liberal" in that it is very old word and many different idealogies can fit under it, but the left and far left has usurped it for itself?
I am not sure about the origins of the word. At present, the far left maniacs have decided to use it as a synonym for "liberal."
A liberal by any other name is just as perverted and crooked (apologies to William Shakespeare Esq.)