Democratic presidential nominee Hillary Clinton is ridiculing her opponent Donald Trump for refusing to say that President Barack Obama was born in America, suggesting that Trump’s history of asking questions on the issue proves he’s a racist.

“Imagine a president who sees someone who doesn’t look like him, doesn’t agree with him and thinks that person must not be a real American,” Clinton said, during a speech to the The Black Women’s Agenda symposium in Washington D.C.

She cited Trump’s criticisms of an Hispanic-American judge and parents of a fallen Muslim-American soldier as proof that he was a bigot and unfit to serve as president of the United States.

Clinton also described Trump’s behavior as sexist.

“He looks at women and decides how our looks rate on a scale of 1-10,” she said with distain.

She urged all women in the audience to fight back, by supporting her in the upcoming presidential election.

“We cannot become insensitive to what he says and what he stirs up,” she said. “We can’t just accept this, we’ve got to stand up to it. If we don’t then it won’t stop.”

Clinton reminded the audience and the media that Trump stoked the birther movement, and claimed that his presidential campaign was “founded on this outrageous lie.”

“Barack Obama was born in America, plain and simple and Donald owes him and the American people an apology,” she said.