COLORADO SPRINGS, Colo. — Billionaire Charles Koch called the notion that he would support Democrat Hillary Clinton in the general election “blood libel,” while doubling down on his assertion that he wouldn’t support Republican Donald Trump.

“The first thing I want to do is correct a rumor that the media keeps stimulating, and that is that I’m probably going to support Hillary,” Koch told a group of about 400 donors. He added, to a round of cheers: “That is a blood libel,” using a term that refers to the anti-Semitic belief that Jews used the blood of Christian children to make ritual bread called matzo.