WYSK: There funded by dark money PACS, but some good reporting has brought out these names: David Koch, Peter Thiel, Reid Hoffman, Mark Cuban, Harlan Crow, and Michael Bloomberg. Some of there members are most famous for stopping big bills. Joe Leiberman, for example, single handedly stopped the single payer portion of the ACA. Senators Joe Manchin and Kyrsen Simena kept the John Lewis voting rights act from passing, and famously kept the senate from repealing the filibuster.
The dems are never going to pass voting reform for the same reason the UK labour party (a considerably further left party than the dems) has never passed it despite pretending they would consider it for multiple decades now. They benefit from FPTP. All they would be doing is diluting their power and handing over a huge portion of the political landscape to socialists who would immediately become relevant, they would then be forced to actually come to agreements with those socialists as opposed to just completely and totally ignoring them as they do currently.