A number of these foundations have individual or family names attached.
My bet would be some of the founding family persons and progeny are political contributors. Obviously these 501(c)(3) operations would not be.
At a guess, the founding families might not be Tea Party aligned. Indeed, some might even give to those against whom the Tea Party regulars rail loudest. Perhaps not.
But another bet, not much traction among folks who established these foundations for "Tax The Rich."
There might be a connection to how "Tax The Rich" made it as a slogan, more so than as a practice.