Senator Kamala Harris offered a preview Wednesday afternoon of how she might respond to attacks from President Donald Trump if she runs against him in 2020: by appealing to Americans’ sense of compassion.

“What would you have said to President Trump about his—his mocking of [Christine Blasey Ford’s] memory at his campaign rally last night?” asked Laurene Powell Jobs, who was interviewing Harris at the The Atlantic Festival in Washington, D.C. (Powell Jobs is the founder of Emerson Collective, which is the majority owner of The Atlantic.)

There was a short pause, as the California Democrat considered the question. “Stop being mean,” she replied, simply but firmly.

The president has been roundly criticized for his remarks on Tuesday night mocking Ford, the California professor who testified that she had been sexually assaulted by Trump’s Supreme Court nominee, Brett Kavanaugh, at a high-school party in the early 1980s. “I had one beer!” Trump told a crowd at a rally in Southaven, Mississippi—part of his dynamic reenactment of Ford’s recent testimony.

“How did you get home?” Trump continued, this time mimicking the prosecutor Rachel Mitchell, who was questioning the professor.

“I don’t remember,” he said, acting as Ford.