New Hampshire voters went to the polls on Tuesday to select nominees for U.S. Senate, Congress, governor and hundreds of state legislative seats, with the retirement of three-term Democratic Senator Jeanne Shaheen driving a cascade of competitive races. The most closely watched contest is the Republican primary to fill Shaheen's Senate seat, where two former senators she previously defeated — John E. Sununu and Scott Brown — are among eight candidates vying for the nomination, while four-term Democratic Congressman Chris Pappas faces a rising challenge from democratic socialist Karishma Manzur on the left. The outcome carries national significance: the New Hampshire Senate seat is considered one of a handful that could determine which party controls the U.S. Senate, with Democrats needing a net gain of four seats to reclaim the chamber.