>> reporter: weeks before that, another progressive blogger posed to make this prank phone call to scott walker. >> hi, this is scott walker. >> scott, david koch, how are you? >> i'm good, and yourself? >> reporter: democratic activists see a curtain being pulled back, revealing one of the most powerful and mysterious forces in politics. >> they've been able to operate in secrecy and use vast amounts of their personal wealth to control our democracy. >> reporter: two of the world's richest billionaires control koch industries, a manufacturing giant with products ranging from petroleum to paper cups. they've used that wealth to back conservative causes aimed at shrinking the size of government. >> campaign contributions, lobbying, the funding of political groups or non-profit groups. >> they seem to be doing it all? >> they seem to be doing it all because they have the ability to do it all. >> reporter: candidate contributions from the koch's