Republican presidential hopefuls are set to woo conservative voters in Iowa at a conference organized by an influential Christian group. Texas Senator Ted Cruz, former Pennsylvania Senator Rick Santorum and mogul Donald Trump are among the speakers at a summit in Ames on Saturday. The Family Leader is the event sponsor. The daylong event will be one of many of its kind in the run-up to the 2016 presidential election. None of the potential contenders appearing Saturday has declared candidacy. Conservative voters could be key to a 2016 victory in Iowa's caucuses, the nation's first presidential nominating event. But the field remains open.