LOS ANGELES (AP) — Donald Trump's campaign said Tuesday that a computer problem resulted in a prominent white nationalist being mistakenly included on a list of his potential California delegates, an embarrassment for a candidate who has been criticized before for being too slow to distance himself from former Ku Klux Klan leader David Duke. Trump California director Tim Clark released a statement faulting a "database error" for the inclusion of William Johnson, which said he been rejected and removed from the campaign's list in February 2016. Johnson, a white nationalist leader and Trump supporter, told The Associated Press that he received an email from Clark earlier Tuesday informing him that his name had been "erroneously listed" as a delegate. Previously, Trump has drawn criticism for hesitating before denouncing former Ku Klux Klan leader David Duke, who said not voting for Trump was "treason to your heritage."