"What’s the George Costanza line? ‘When they're applauding, you sit down’?"
-- Mitt Romney at last night's CNN Republican presidential debate
No, the line is actually from Jerry directed at George and it goes, "Showmanship, George. When you hit that high note you say goodnight and walk off." (It's the same episode in which Puddy utters the famous line, "You stole my Jesus fish!" and which also has Kramer and Mickey acting out diseases for med students and Jerry trying to figure out what his new girlfriend's "tractor story" is.)
The best response to Romney's failed stab at a completely untimely pop culture reference came from Vanity Fair, which said that "household appliance" Romney "took a new HUMAN CULTURE (ca. 1990 A.D.) cartridge out for a spin," but may have purchased some second-tier software.