The Trump campaign submitted the name of William Johnson, the head of the American Freedom Party who funded pro-Trump robocalls that talked of the white race "dying out in America," to the California secretary of state. Johnson is one of 169 delegates -- 159 from congressional districts and 10 at-large delegates -- that voters in each of California's congressional districts would send to the GOP's nominating convention this summer by voting for Trump.
Johnson said he received an email from a California strategist with Trump's campaign late Tuesday afternoon stating that he had been listed in error.
In a telephone interview with CNN, Johnson said he understood that "a campaign has to put its best foot forward — and I'm a white nationalist, and we live in a society today where white people don't like white people who like white people. And so, I don't want to do anything that would jeopardize Mr. Trump's chances. So it's best that I resign."
Johnson praised Trump on Wednesday, telling CNN's "The Lead with Jake Tapper," that he like the real estate mogul for speaking his mind.
"Mr. Trump is the real deal. He will not govern by public opinion poll. He says what's on his mind," Johnson said, who described his ideology as making American's aware of the "precipitous decline in the white race."
The Trump campaign on Tuesday blamed Johnson's inclusion on its California delegate slate on a "database error."
"Yesterday, the Trump campaign submitted its list of California delegates to be certified by the Secretary of State of California. A database error led to the inclusion of a potential delegate that had been rejected and removed from the campaign's list in February 2016," Trump campaign spokeswoman Hope Hicks said in a statement.
"We are working to correct this error," she added.
Johnson is slated to serve as a Republican delegate at the convention should Trump win California's 34th congressional district.
Trump is now the Republican Party's presumptive nominee and is running unopposed as he looks to secure the final round of delegates he needs to reach the 1,237 threshold to formally win the GOP nomination.
Trump's campaign manager, Corey Lewandowski, said his team was also looking into the California delegate slate rules.
"I don't know if he is being replaced or not -- I don't know the answer to that, but I'm sure we'll find out, and as soon as we know whether he's being replaced or not, we'll make sure you're made aware of it," Lewandowski said.
Johnson said he bore no ill will toward the campaign and immediately told the Trump campaign he would withdraw as a delegate.
"So that there is no misunderstanding and for clarification, I hereby resign as a delegate," Johnson wrote to Clark. "Good luck."