Susie Tompkins Buell, a Democratic megadonor, has begun sending out invitations to a fundraiser for Pete Buttigieg’s presidential bid.

On Thursday, Buell, who in the 2020 presidential cycle has been an early backer of Sen. Kamala Harris’ campaign, emailed friends about the April 11 fundraiser in San Francisco.

“I have had numerous conversations with many engaged, caring and deeply invested individuals about the Democratic prospects of winning back the White House in 2020. One thing stands out from these conversations — people are intrigued by Pete Buttigieg,” said the email, which was signed by Buell, her husband, Mark, and friends Swati Mylavarapu and Matt Rogers and was obtained by POLITICO. “How has this 37-year old Rhodes scholar war veteran and openly gay South Bend mayor risen from being largely under the radar to raising $7 million in the first quarter of his presidential campaign? We’d like to know!”

The fundraiser asks for donations starting at $250 and going up to $2,800. Buttigieg has not formally announced that he’s running, but he has formed a presidential exploratory committee, and his team said earlier on Thursday that he would make a special announcement in South Bend, Ind., on April 14.