I didn’t find this by doing a search, so I assume no one has posted about it yet. (If so, feel free to fold this into another thread.)
HBO is currently running a documentary called “Meet the Donors: Does Money Talk?” It was made by Alexandra Pelosi (yep, Nancy’s daughter) where she interviews a number of big donors. Few of the really big ones, of course, because most wouldn’t consent to an interview. No Kochs here, sorry. There’s also a section where she interviews donors and activists specifically focused on controlling campaign finance.
And, there’s a companion page on HBO’s website:
http://www.hbo.com/documentaries/meet-the-donors-does-money-talk/
Give it a watch if you get HBO and have the chance.