Ohio Gov. John Kasich took GOP presidential nominee Donald Trump to task Wednesday for alleging the election could be “rigged.”

“Look, to say that elections are rigged and all these votes are stolen – that’s like saying we never landed on the moon, frankly,” Kasich told CBS This Morning. “That’s how silly it is.”

Kasich was responding to Trump’s suggestion that if he loses Nov. 8 to Democrat Hillary Clinton, it will be because of “large-scale voter fraud.”

“That is a big, fat joke,” said Kasich, who ran against Trump in the GOP primary and has refused to endorse the Republican nominee.

While voter fraud does happen, academic studies, government research, court statistics and elections officials all indicate it is not a significant problem. Lawmakers, many of them Republican, use voter fraud as a reason for implementing stricter voting laws, but actual instances of fraud are rare.