(CNN) - John McCain – who had vowed to avoid negative campaigning – defended his decision to send out a campaign mailer in South Carolina attacking Republican rival Mitt Romney, describing the move as a defensive measure.
“We had to respond to negative campaigning,” the Arizona senator told reporters after a campaign event in Kalamazoo, Michigan.
“Now, we won’t go tit-for-tat, but we will respond, and we will make clear that this kind of negative campaigning didn’t work for him in Iowa when he attacked Governor Huckabee, didn’t work in New Hampshire when his campaign attacked me, and I don’t think it’s going to work in Michigan where he’s attacking me, and it won’t work in South Carolina.
“So, we will respond in a very forceful fashion because we know unfortunately that these charges have to be responded to, but we’re not going to go tit-for-tat with him.”
He added, “…There’s a stack of mailers this high that attack me, literally this high that have flooded South Carolina for the last six months.”
He also dismissed the idea that the mailer was not a response to a Romney charge, but a fresh attack of his own against the former Massachusetts governor.
“It’s not negative campaigning,” McCain said. “I think it’s what his record is, particularly his positions on many issues… It’s a tough business. I said it in the debate the other night. It’s a tough business for all the candidates that are running. When millions of dollars are spent attacking us, we are going to have to respond.”
South Carolina's Republican presidential primary will be held this Saturday.
–CNN’s Dana Bash and Rebecca Sinderbrand