Is ‘Scots-Irish’ supplanting ‘Scotch-Irish’?

“I love that you said ‘Scotch-Irish’ instead of this new term ‘Scots-Irish’ that you hear….”

— D.G. Martin, interviewing Walt Wolfram on “North Carolina Bookwatch” (May 18)

I was surprised to hear “Scots-Irish” described as the newer usage, but sure enough….