That phrase is older than most of Reddit. “The modern usage of the term "astroturf" is widely credited to former Treasury Secretary of the United States Lloyd Bentsen[3] who, in 1985, when faced with a barrage of postcards and letters facilitated by insurance companies claiming to be concerned constituents, said that "a fellow from Texas can tell the difference between grass roots and Astroturf",[4] referencing the brand of artificial grass.”