The Santorum Preference Cascade Recedes

Americans, perhaps because of the speed of mass media nowadays, tend to be susceptible to bubbles both in economics and politics.   The successive performance of the series of "not-Romney" candidates over the past six months, from Michelle Bachmann's success in the Iowa straw poll, to Rick Perry's entrance into the campaign, to Hermann Cain's meteoric rise and fall, to Newt Gingrich's zombie-like return from the dead, and finally to Rick Santorum's rise after the Iowa caucaus and then again after the mid-February caucuses, resemble nothing so much as a series of crazes, of mass hysteria, as Republican "investors" chase the next tulip (or the next Iraqi dinar re-val).    Every time, the hysteria fades, and Mitt Romney, the sensible-shoes candidate, surges back into the lead.  

At least that's how I read this graph from Gallup: