Who would be funding the Institute for Paid Advocacy for this?

It's been noted on Twitter that the IPA is running a campaign arguing that "race has no place in the constitution".

I'm curious as to which person/companies with money to spare would be funding the IPA to do this.   Gina "it's a pity I can't pay my workers $2 a day" Rinehart?   (Whose company, incidentally, just made a $2.6 billion profit.  Gee, I guess paying workers more than a pittance still allow her to make a profit.  Who knew?)  

But I could be wrong.  It could another ageing, shadowy, rich conservative who doesn't like to make the case him or herself directly.  But it just seems to me an odd thing to want to spend money on.