"There were all sorts of liberal talk shows, both TV and radio, but they were at night, and the people who think as you and I do had to endure being laughed at and made fun of and impugned on a daily basis. And finally, here came a guy, Rush Limbaugh, who didn't tell you what to think but simply reflected what you already thought, what you already believed. He validated what you already thought and believed." [1]
Saying "dittos" (or even "mega-dittos") was started by a Rush Limbaugh caller as a shorthand way for callers to say they liked the show and to save time.
[1] (http://www.rushlimbaugh.com/home/daily/site_100801/content/lucky.guest.html) Rush Limbaugh: I Am A Lucky Man. (Transcript of Limbaugh's announcement that he lost his hearing.)
wikipedia.org dumped 2003-03-17 with terodump