Former President Barack Obama was “actually my greatest disappointment,” liberal megadonor George Soros said in an interview published by The New York Times on Tuesday.

An early supporter of Mr. Obama’s 2008 election campaign, Mr. Soros told The Times that he felt let down on a professional level by the lack of attention he received from the former president during his eight years in office.

Mr. Obama “closed the door on me” after he was elected, Mr. Soros said in the interview. “He made one phone call thanking me for my support, which was meant to last for five minutes, and I engaged him, and he had to spend another three minutes with me, so I dragged it out to eight minutes.”

“He was someone who was known from the time when he was competing for the editorship of The Harvard Law Review to take his supporters for granted and to woo his opponents,” Mr. Soros added.

Mr. Soros subsequently committed over $25 million during the 2016 U.S. general election to presidential hopeful Hillary Clinton and other Democratic candidates, according to federal records.

He said he would be open to potentially funding moderate Republicans such as Sens. Lisa Murkowski of Alaska and Susan Collins of Maine, but cautioned his support would likely hurt either’s prospects.

“I don’t particularly want to be a Democrat,” Mr. Soros told The Times.