Then, a man yelled out: "Waterboard Hillary!" a clear reference to Democratic presidential candidate Hillary Clinton.
Many in the crowd quickly reacted to his comment with a laugh. Rubio appeared to laugh it off as well.
"I don’t want to know what he said," responded Rubio, adding: "The press is here, I didn’t even hear what they — I didn’t hear what they said. I know it wasn’t a bad word, that’s all that matters."
Politicians have come under criticism for not rebuking controversial comments by supporters. At a rally last year, for example, Donald Trump did not challenge an audience member who said that President Obama is Muslim and "not even an American."