Donald Trump could put the “Star of David” tweet to rest if he would apologize and acknowledge that the perceived offense caused harm, ADL’s CEO Jonathan Greenblatt said on Tuesday.

“He should just admit the offense [and] apologize,” Greenblatt said in an interview on “CNN Tonight” with Don Lemon late Tuesday. “I think this would satisfy all of the public – on the right and the left, Democrats and Republicans. Just say, ‘White supremacists, extreme right, you have no place in my campaign. Hate has no place in the public square, and you have nothing to do with making America great again.'”

According to Greenblatt, if the presumptive Republican presidential campaign would “clearly and unequivocally” disavow the support from David Duke, the KKK and white supremacist groups, “this issue would be over.”

Professor Alan Dershowitz, also appearing on the program, predicted the controversy would hurt Trump’s support among Jewish voters. “I already have heard from four or five Jewish voters who were thinking of voting for him, Republicans, who said say this crossed the line,” Dershowitz, a Hillary Clinton supporter, said. “I think it will hurt him, but it will help him with people on the extreme, extreme neo-nazi right.”

Public criticism of Trump’s weekend tweet against Hillary Clinton, which included an image of Clinton and a Star of David created by a racist Twitter user and circulated by white-supremacists, entered its fourth day after a New York Observer entertainment writer Dana Schwartz published an open letter to the publication’s publisher Jared Kushner, criticizing his tacit approval of Trump’s use of anti-Semitic imagery.

“Please do not condescend to me and pretend you don’t understand the imagery of a six-sided star when juxtaposed with money and accusations of financial dishonesty,” Schwartz, who is Jewish, wrote in her letter published on the Observer’s website. “I’m asking you, not as a ‘gotcha’ journalist or as a liberal but as a human being: how do you allow this? Because, Mr. Kushner, you are allowing this.”

Kushner later issued the following statement: “My father-in-law is an incredibly loving and tolerant person who has embraced my family and our Judaism since I began dating my wife. I know that Donald does not at all subscribe to any racist or anti-semitic thinking. I have personally seen him embrace people of all racial and religious backgrounds. The suggestion that he may be intolerant is not reflective of the Donald Trump I know.”