DRAMATIC political change is sweeping Spain, or so polling suggests. For three decades Mariano Rajoy’s conservative Popular Party (PP) and the Socialists have taken turns to run the country. Now their support is crumbling (see chart) and a two-party system that guarantees stable governments is at risk.Two recessions in five years and 27% unemployment have shaken faith in the status quo. And as bond markets are getting the jitters again, promises of a return to growth this year have failed to restore shattered confidence. Corruption, cronyism, entitlement and a lack of transparency have helped persuade voters that the system which served their fledging democracy so well has become a liability.Backing for the PP has shrivelled from 45% to 24%. Yet under Alfredo Pérez Rubalcaba the Socialists have failed dismally to capitalise on the growing discontent. Instead, support has shrunk from 29% in the elections of November 2011 to around 21%. Elections are not due until late 2015, but Spain is on track for its weakest government since democracy was restored in 1977.If Spaniards want to throw out the old order, what other choices do they have? Two parties are mopping up the…