"Oh, look at my African-American over here. Look at him," Trump said. "Are you the greatest?"
The remark didn't generate a noticeable response from Trump's audience.
Trump campaign spokeswoman Hope Hicks told CNN Trump was "just referring to a supporter in the crowd. There's no ill will intended, obviously." She added Trump was "grateful for this person's support."
Hicks also rejected the suggestion that Trump's use of the possessive "my" to refer to the supporter was racist, saying such a charge was "ridiculous."
Gregory Cheadle, a Republican California congressional candidate, confirmed to CNN he was the supporter to whom Trump pointed. He told
the Record Searchlight, a local newspaper, he was happy to be cited by Trump.
"That was me seriously. I got two autographs out of that," Cheadle told the newspaper. He added, "To give the black folk the time of the day, I was happy."
Trump's remark came as he recalled an incident in March when a black supporter of his assaulted a protester
at a rally in Arizona as he was being escorted out of the building by police.
The comment also comes as Trump is under fire for calling on the federal judge presiding over one of the lawsuits against Trump University to recuse himself because of his Mexican heritage.
Trump again argued Friday
in an interview with CNN's Jake Tapper that the judge is inherently biased against him because of the presumptive GOP nominee's plan to build a wall along the U.S.-Mexico border.
"If you are saying, he can't do his job because of his race, is that not the definition of racism?" Tapper asked him.
"No, I don't think so at all," Trump replied. "He's proud of his heritage. I respect him for that."
The presumptive Republican nominee has repeatedly hit back at charges that he is racist by insisting he is "the least racist person that you have ever met."
But Trump's rhetoric has repeatedly drawn charges of racism, xenophobia and Islamophobia.
In November, Trump retweeted
a graphic of false crime statistics comparing percentages of "blacks killed by blacks" and "blacks killed by police" that included an image of a dark-skinned man wearing a bandana, military-style pants and holding a handgun sideways.
The graphic vastly overstated the number of homicides committed by blacks.
Trump kicked off his campaign by calling some undocumented immigrants from Mexico "rapists"
and criminals and then stoked Islamophobic sentiment in December
by calling for a "total and complete shutdown of Muslims entering the United States."
Trump said in March that he believes "Islam hates us"
and said last fall that a Black Lives Matter protester who disrupted his rally and was kicked and punched by Trump supporters probably "should have been roughed up."
Still, Trump has insisted that his campaign message will have enormous appeal among minority communities, particularly African-Americans and Hispanic Americans.
The de facto Republican nominee insists that his promise to bring jobs back to the U.S. and reduce unemployment in minority communities will draw those groups to his controversial candidacy.