rolling thunder
n.— «Rolling Thunder. We don’t need Michael Fish to explain this one: a poll of, say, a constant 1,000, but each day knocking off a set number and replacing them with newcomers, to give continuity while freshening things up. Critics say Rolling Thunder wrongly boosted John Kerry.» —“Breaking the code” Guardian (U.K.) Apr. 11, 2005. (source: Double-Tongued Dictionary)