Trump has been smearing McCabe repeatedly on Twitter and has done so in the most disrespectful way, something the will definitely not go unnoticed by the rank and file of the FBI.
He was fired specifically by US Attorney General Jeff Sessions, who said an internal review found he leaked information and misled investigators.
Mr McCabe denied the claims and said he was being targeted because of his involvement in the inquiry into alleged Russian meddling in the 2016 election.
Mr Trump has long accused Mr McCabe of bias in favour of the Democrats.
He immediately praised Mr Sessions’ decision to fire him.