SCOTT WALKER is in and he’s sounding regal. “We fought and we won,” he says in his first promotional spot. “We won four elections in three years in a blue state ... We did it by leading; now we need to do the same thing for America.” The use of the first-person plural may be intended to convey modesty, a generous sharing of credit by a politician accustomed to personal triumph. Yet it also suggests that Wisconsin's governor would like you to think of him not as a mere man, but as a movement. From where he stands, at the top tier of contenders for the GOP nomination, there are good reasons for him to hope that you will. Mr Walker’s pitch, to primary voters at least, is that he is the candidate who can win elections without compromising conservative values. Like Ted Cruz, the junior senator from Texas and another contender for the Republican nomination, Mr Walker has correctly identified that conservative primary voters are fed up with constantly being told that they need to change or hide their opinions in order to win elections. But Unlike Mr Cruz, a conservative representing a conservative state, Mr Walker makes this argument in a place that last went for a Republican presidential candidate in 1984. And yet, there he is in the governor’s mansion. What electoral magic is this?

A closer look at Wisconsin suggests that Mr Walker’s formula is rather less impressive than he might have you believe. The Marquette Lawyermakes a convincing argument that, far from being a cosy mid-Western place where everybody gets along just fine, Wisconsin has become one of the most politically polarised states in America. Voters in the state are increasingly likely to live in politically like-minded “silos”, in counties that are clearly delineated as either red or blue. Metropolitan Milwaukee, for example, is characterised by a concentrated urban core of Democrats surrounded by Republican suburbs. In the 2012 presidential election only 12% of the state’s voters lived in wards decided by single digits.