I bet Obama has done a lot of spying, thanks to corrupt FBI/DOJ/IC. When they got the goods on a political enemy, they put the squeeze on them and when necessary, went to corrupt FISC judges to get FISA approval AFTER the fact. Supreme Court, congress, candidates, and who knows who else have been victims.
This is going to be BIG.
You capture the key point in all this: How far back does FISA spying on innocent politically-attached people go?
But this article helps confirm what WE already know: the Elite-DC-politician-media-lobbyist complex is strong.