Donald Trump accused debate moderator Anderson Cooper of CNN of ganging up on him, leaving the GOP nominee fighting "one-on-three" in Sunday night's second presidential debate.

After Hillary Clinton's long explanation of her use of her private email server, saying she made "a mistake and I take responsibility for using a personal email account," and no "classified materials ended up in the wrong hands. I take classified data very seriously and always have."

"And yet she didn't know the . . . letter C on a document," Trump snapped. "Right? She didn't even know what that letter meant. It's amazing."

"I'm watching Hillary go over facts, and she is go after fact after fact and lying again because she said what she did with e-mails was fine," he continued. "You think it was fine? I don't think so. She said that 33,000 e-mails had to do with her daughter's wedding and a yoga class. Maybe we will give three or five, but 33,000 e-mails deleted and she said there was nothing wrong. That was after getting a subpoena."

"For you to say that there was nothing wrong with you deleting 39,000 e-mails, again, you should be ashamed of yourself," he scolded.

When Cooper interrupted and said, "We have to move on. We have to give the audience a chance," Trump added again: "After getting a subpoena to the United States."

"We have to move on," Anderson pressed.

Clinton then interjected: "It's just not true," to which Trump asked: "You didn't delete them?"

"They were personal e-mails and not official. We turned over 35,000," Clinton responded.

"What are about the other 15,000?" Trump pressed.

"Please allow her to respond," Anderson interjected. ""She didn't talk while you talked. "

"That's true. I didn't," Clinton replied, smiling. "In the first debate, and I will try not to on this debate, because I want to get to the questions people brought to us tonight. "

"And get off this question," Trump jabbed.

"Okay. Donald. I know you are into big diversion, anything to avoid talking about your campaign and the way Republicans are leaving you, but," Clinton snapped.

Cooper then announced he wanted to go on to an audience question about healthcare.

"Why aren't you bringing up the e-mails?" Trump bluntly asked Cooper. ""It hasn't been finished at all."

"One on three," the GOP nominee grumbled, turning his back to the moderators.