MADRID — Spain’s conservatives hope a trio of impending regional elections will collapse the government of Socialist Prime Minister Pedro Sánchez, the EU’s only remaining heavyweight national leader from the center left. First up this Sunday is the northeastern region of Aragón, dubbed the “Spanish Ohio” thanks to its track record as a barometer of the national mood. The center-right People’s Party (PP) appears to be heading for victory, but a surging far right is likely to make the biggest