Rubio told CBS "Face the Nation" host John Dickerson that he purchased the firearm on Christmas Eve because he's not in town often, but was home that day. He added that he was already a firearm holder.
"I'm a strong supporter of the second amendment. I have a right to protect my family if someone were to come after us," Rubio said. "In fact, if ISIS were to visit us, or our communities, at any moment, the last line of defense between ISIS and my family is the ability that I have to protect my family from them, or from a criminal, or anyone else who seeks to do us harm. Millions of Americans feel that way."