Donald Trump Jr. was bashed on Twitter Saturday for boosting a type of “birtherism” campaign against Sen. Kamala Harris (D-Calif.) that surged in the wake of her breakout performance in one of the recent debates among Democratic presidential candidates.

A right-wing operative attacked Harris on Twitter after the debate, claiming she had no right to represent American blacks because her father grew up in Jamaica. Harris, who is of Indian and Jamaican heritage, was born in Oakland, California, in 1964.

The attack went viral thanks in part to Donald Jr.’s retweet and an assist from Twitter accounts identified as bots. The onslaught echoed the “birther” campaign against Barack Obama that falsely claiming he was born in Africa and couldn’t legally be president. Donald Trump (with wife Melania ) was a leading voice among a group of conspiracy theorists that promulgated the Obama birther lie.

Earlier this month, Trump son-in-law Jared Kushner refused to directly answer whether Trump’s birther lie about Obama was racist.