U.S. Sen. John Kirk, R-Ill., raised his left hand, instead of the traditional right, during his swearing-in on the instructions of Vice President Joe Biden.

ADVERTISEMENT

Biden, whose duties include serving as president of the Senate, began Kirk's swearing-in Monday by instructing him to "please place your right hand on the Bible," the Chicago Tribune reported Wednesday.

Kirk followed Biden's instructions and placed his right hand on the book, raising his left while repeating his oath.

"Senators-elect affirm their oath to defend the U.S. Constitution by stepping forward, raising their right hand, and repeating the words spoken by the presiding officer," reads a passage from "Traditions of the United States Senate" by Richard Baker, U.S. Senate historian from 1975 to 2009.

Donald Ritchie, the current Senate historian, said the switch has no bearing on Kirk's standing as a senator.

"The importance of the oath is that you agree with the oath, not that you raise a particular hand or you hold a particular Bible," he said. "All are completely secondary to your commitment to upholding the Constitution and supporting the United States."