I don't think it's the corporations, I am pretty sure it's the big foundations. The Rockefeller Foundation, Carnegie, Ford, Guggenheim Fellowship, etc. The large Tax-Exempt Foundations have been changing society since 1909. What the Reece Commission in 1953 found will shock you! Listen to lead investigator Norman Dodd be interviewed by G Edward Griffin on youtube. We are in an oligarchy and these foundations are their tools.
I don’t doubt that the foundations play a big role in this but corporations play a big role too.
As you can see, their Corporate Partners are listed on the linked site:
http://www.hrc.org/the-hrc-story/corporate-partners
Platinum Partners
Gold Partners
Silver Partners
Bronze Partners