>> we are going to drain the swamp. >> we tested things like "drain the swamp." we started testing before they gained prominence in american >> reporter: as recently as last night, the president acknowledged "drain the swamp" was not his own creation. >> it was a term that was actually given to me. usually i like to think them up myself, but this was given to me. >> reporter: cambridge analytica now under fire for gaining access of the personal data of up to 50 million americans through their facebook accounts. they obtained that information from this man, russian-american data scientist aleksander kogan, who insists he didn't know he was breaking any rules. >> did they tell you what they were going to do with their data? >> no. i knew it was for political consulting, but beyond that, no idea. >> reporter: on "60 minutes," brad parscale, who ran trump's 2016 digital strategy and is now the 2020 campaign manager, described facebook as their ace in the hole. >> i understood early that facebook was how donald trump was going to win.