Donald Trump is blaming a “database error” after it was revealed that a white supremacist was a delegate for the presidential hopeful at the Republican National Convention.

William Johnson, head of the white nationalist American Freedom Party, has been politically active since an unsuccessful first run in a 1989 congressional campaign.

Trump was slow to distance himself from the Ku Klux Klan earlier in 2016, which many white supremacists took as a subtle nod of approval in their direction. The campaign has gone on to garner enthusiastic support from white supremacists, many of whom feel Trump speaks directly to them.

However, the Trump camp says the inclusion of Johnson as a delegate was simply a computer glitch.

“Yesterday, the Trump campaign submitted its list of California delegates to be certified by the Secretary of State of California,” spokeswoman Hope Hicks told the press in a statement. “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.”

Johnson said Tuesday that he will resign as a Trump delegate. Earlier this year, Johnson made robocalls on behalf of the Trump campaign that sought support with a message that included the quote “the white race is dying out.”

The story was originally reported by Mother Jones and noted that Johnson and Trump’s California delegate coordinator, Katie Lagomarsino, were communicating with and congratulating Johnson as recently as Monday.

While Johnson’ resignation is in place, some political analysts feel the damage has already been done.

NEW: White Nationalist William Johnson remains on Trump's delegate list. Statement from CA Secretary of State Spox: pic.twitter.com/v7DNg0QE7v

— Candace Smith (@CandaceSmith_) May 11, 2016