The Maryland governor is filling the void in Iowa, New Hampshire and beyond during the early stages of the 2016 presidential race, campaigning for fellow Democrats and making personal appeals while former Secretary of State Hillary Rodham Clinton remains the prohibitive — if yet undeclared — favorite. In the summer before November's mid-term elections, Clinton's dominant position in a hypothetical field has limited Democrats' activities in early presidential voting states even while an ambitious slate of Republicans descend. O'Malley was returning to Iowa on Saturday, headlining a fundraiser for state Sen.