If wiretapping occurred last fall at Trump Tower, and it does appear the DOJ got a warrant from a FISA court judge to do so, did the FBI actually carry it out? If so, what did they find out? Was there collusion with the Russians? There's no evidence of that.
On the other hand, if it was not carried out, why not go through with it?
Fear of a finding a dry hole?
Wiretapping has certainly been done in the past under Pres. Obama, when he was in office. It was done on friends and foes alike. Here is a list, proffered by WikiLeaks, and now picked up by other sites, about wiretapping done folks such as on Tea Party activists targeted by the IRS, reporters, (James Rosen and family), and even Heads of State (Angela Merkel, Benjamin Netanyahu).