Of course they knew about it, Biden was Obama’s Secretary of State and Obama was using the FBI to keep tabs on everything. He already knew that he couldn’t trust Biden.
Actually, Hillary was Obama's SOS, Biden was VP.
From what I understand, Obama's preferred candidate was Cory Booker. Obama didn't want Biden to run. But when he won the primaries, Obama had no choice but to support Biden.
I thought Biden was Obama's VP.
But don't ask Biden; he doesn't remember things like that.