If there was, in fact, incidental collection on the Trump campaign under a FISA warrant -- and multiple collections, hence, "calls" -- then Trump has far bigger problems than whether or not "Obama wiretapped me."
You lawyer types know this, but for the rest of you: FISA warrants are issued when there's evidence to suspect a person inside the U.S. of espionage. FISA warrants are not handed out lightly. We do it a lot, but there is a lot of spying going on. Like, a lot, a lot. And if you're a politician, you do not want your phone to be one of the ones that anyone being monitored under a FISA warrant is calling. Especially repeatedly. Holy shit, just no.
Again, that word, "calls." As in, multiple. Damn.
Technically, Trump's campaign may not have been "tapped" -- which would explain the DNI's statement that there was never an order for a FISA warrant covering Agent Orange; that could be technically true -- but if people whose phones were being tapped on suspicion of espionage were calling Trump's campaign headquarters, well, then, "Lu-u-u-u-cy, you got some 'splainin' to do."
If this is factual, then this is gonna be really cool. We could be seeing arrests inside the White House for espionage charges, and possibly shortly. That will be some quality TV.
Man, we live in heady times.