(CNN) Sen. Cory Gardner, the chairman of the National Republican Senatorial Committee, said Monday that if Alabama Republican Senate nominee Roy Moore "refuses to withdraw and wins, the Senate should vote to expel him."

Gardner said in a statement, "he does not meet the ethical and moral requirements of the United States Senate."

There have only been 15 expulsions in US Senate history.

Earlier Monday, Senate Majority Leader Mitch McConnell told reporters that Moore should step aside. Later McConnell was asked as he left the US Senate floor, if Moore should be expelled if he is elected.

"I said this morning all I'm going to say today," McConnell responded. "And others are speaking for themselves and you all are reporting it."

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