The Democratic Alliance's (DA) candidate list, released on Saturday, contains a number of former ANC members but none of the defectors are likely to attract the ruling party's ire quite like Mackenzie.
Mackenzie does not have a high public profile and never held high office in the ANC but his defection to the DA, revealed on Saturday, is going to make at least one high-ranking ANC official unhappy.
"He has been a committed member of the ANC most of his life but in recent times has come to believe that it is the DA that offers the best hope for the future of South Africa," the official opposition said of Mackenzie, who it considers to be a prospective parliamentarian, depending on the number of seats it wins in elections likely to take place in April.
What it does not mention is the close association that Mackenzie still has with Sports Minister and ANC firebrand Fikile Mbalula. On paper, Mackenzie is still Mbalula's private secretary.
"I think he knows," Mackenzie told the Mail & Guardian on Saturday. "I told the chief director of corporate services [of the department of sport and recreation] on Friday, and they are personal friends."
On making the disclosure, Mackenzie said, he was told the matter would be handled on Monday. He suspects his defection will "not be well received".
Mbalula and his representatives could not be reached for comment on Saturday but the minister is unlikely to be impressed.
Though still listed as the minister's private secretary, Mackenzie said he had been on secondment to the World Anti-Doping Agency for the past seven months, so had some distance from his office.
Mackenzie has also been the office manager in the sport ministry and was previously a director in the presidency under Thabo Mbeki.