"Santa is still just Santa. Kids are very innocent, they just love Santa," added the former army vet, who has been a professional Santa for 17 years.
The reaction from some adults has been anything but innocent, however.
Negative comments on the WCCO website run the gamut from confused to outright hateful.
"Santa is NOT black!! that is a nasty lie and horrible thing to subject children to!' John Armstrong posted. 'My god people! ..holycow thank god I DO NOT go to malls anymore."
Other users made racist jokes about black people, including one man who said a black Santa would 'steal people's presents' and another who talked about how "HO HO HO rolls off this Big Pimpin' Santa's tongue".
Even more shocking remarks came from Peter Morgan, who said "Santa is WHITE. BOYCOTT Mall of America. Maybe they should change their name to MALL of RAGHEAD LAND."
And a poster under the name Laquisha Reynolds made a series of vicious remarks, referring to Jefferson's hiring as 'an atrocity' and claiming that 'blacks [ate] each other in Africa'.
She also said that if Martin Luther King Jr were to be played by a white man "blacks would try to kill him".
Other comments, worse than these, made repeated use of the N-word and equally appalling slurs.
The Star Tribune shut down its comments on the page about Jefferson, according to an editor there. The writer of the article later said "We routinely turn off comments on articles involving racial issues".
Twitter saw complaints from many too. @Brad_D80 replied to a CNN report about Jefferson's appointment with: "Oh boy racial racist identity politics reporting from CNN.Only you racist lefty types actually care."
But @HiHoney333 was outright venomous, saying a black Santa shows "there's nothing too sacred to muddy up" and called for "black genocide".
The user apparently later deleted that remark.
And user @tlange92 called Jefferson's hire a "catastrophe" and made a series of racist black Santa jokes, including: "why were black Santas reindeer tired? the reindeer had a tough time pulling his stolen hummer".
Thankfully, there were plenty of positive remarks to balance out the relentless racism and negativity.
Several people pointed out that St Nicholas was born in the 4th century in what is now Turkey, and was traditionally shown to have dark skin.
Twitter user @levantina joked: "White people are offended at a black Santa...y'all gonna be blown away when you find out where Jesus is from...'"
And Japanese-American Star Trek actor and playwright George Takei, 79, who was interned during WWII, said: "Watching people meltdown over a Black Santa in the Mall of America. 'Santa is white!'
"Well, in our internment camp he was Asian. So there."
Mall of America is home to a "Santa Experience" until December 24, although Johnson's four-day stint there ends Sunday - as was always planned.
