"So, here's a political psychology question. Why did opponents gullibly swallow the stimulus terminology, and thereby defeat? Any ideas?"
"What’s in a name—the political psychology of ‘stimulus’' by David Hirshleifer,
Many of the opponents of the current stimulus package were supporters of the Economic Stimulus Act of 2008 of President Bush. So stimulus has probably become a lingua franca.
(HT Marginal Revolution)