WASHINGTON (AP) — Moderate, secular and well-educated people propelled Mitt Romney to victory in Ohio's Republican presidential primary on Tuesday, an exit poll of voters showed. Rick Santorum drew robust support from the state's most ardent conservatives and eked out a modest margin among the working class, whom he has targeted in his drive to slow Romney's march toward the GOP nomination.

Ohio was the most closely watched of the 10 states holding Super Tuesday presidential contests. With many viewing it as one of Santorum's best chances of emerging as the singular challenger to Romney, the two men essentially carved the state's party into competing ideological halves.

In two states where Santorum triumphed, Oklahoma and Tennessee, Santorum was buoyed by voters who said their choices were influenced by religion, the exit polls showed.