"Most people use quotation marks and reference the source when they are copying and pasting."

It's from the conservative rag called the National Review. The magazine's current editor is Rich Lowry. Many of the magazine's commentators are affiliated with think-tanks such as the Heritage Foundation and American Enterprise Institute. Prominent guest authors have included Newt Gingrich, Mitt Romney, and Sarah Palin in the online and paper edition.

That's why he didn't want to reference the source because it would call into question the content.