POLITICS is not about policy. Newt Gingrich's striking victory in South Carolina is a beautiful illustration of the idea of expressive voting, which is pithily captured by Robin Hanson's slogan . The idea that political behaviour is expressive rather than instrumental—that we vote not to maximise the chances that our policy preferences will be implemented by government, but instead to send a message to ourselves and others about who we are, and what we care about—is meant to overcome a number of flaws in simple economistic accounts of voting. (Here is a useful lecture outline on expressive voting. Here is an informative review essay covering recent work on expressive theories of voter decision-making.)

Mr Gingrich's big win in the Palmetto State is a fascinating case study of expressive voting because he is in many ways the worst possible herald for principles conservatives claim to hold dear. As Conor Friedersdorf of the Atlantic pithily puts it, Gingrich is "a pompous, erratic, undisciplined serial adulterer who took $1.6 million to peddle influence on behalf of Freddie Mac, [and] supported everything Tea Partiers insist they hated about the Bush Administration... ". What message, then, does a vote for Newt Gingrich express? What message is so compelling that South Carolina voters were willing to overlook Mr Gingrich's overwhelming liabilities as a candidate? "We think open marriages are great!"? "We love corrupt Washington insiders"? I guess not. Saturday's expressive message, I think, comes down to this: "We're not going down without a fight!"

Mr Gingrich's bristling retort to Juan Williams about race and his ferocious attack on John King's question about his ex-wife's allegations amounted to a sort of fantasy-fulfillment for many white, conservative Christians aggrieved by the erosion of their cultural dominance. Mr Gingrich took what indignant conservatives yell at their televisions, dressed it up in soaring rhetoric, and barked it at the business end of the TV camera. "Screw you and your superior P.C. bullshit, Juan Williams! Screw you and your sleazy anti-conservative, character-assassinating 'journalism', John King. You 'elites' are not better than us. This is our country, not yours. Our values set the standard, not yours." To all this, South Carolina's Republicans said "Woooo!"

Mitt Romney can prattle on all he likes about his picture-perfect marriage, about double-Guantanamo, about America, the best doggone shining city on a hill in the history of forever, but this stale stuff has never hit conservatives where they live, in the victim-bone. Mr Romney can mouth the words, but he's just too sober, too Wall Street, too Mormon to really feel the down-home conservative music. As nuts as it may seem to those of us who belong to smaller, more vulnerable segments of the population, conservatives feel backed into a corner by the broader culture, and they detect in Mr Gingrich's pharisaic diatribes the hopeful will to fight, the promise of punching their way back to uncontested supremacy. That Mr Gingrich is a cartoon of a corrupt demagogue doesn't seem much to matter. Not only do conservatives believe Mr Gingrich feels their pain, they believe he seeks their revenge. That's thrilling.

Mr Romney's challenge tonight is to talk conservatives down from the ledge without worsening his position by insulting them for climbing up there with Newt in the first place. It will help if he can offer an answer to the question "What does a vote for Mitt Romney express?" other than "reconciliation to a disappointing inevitability".

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