NORTH HAMPTON, N.H.—The race for New Hampshire's open Senate seat has yet to attract the sort of national media attention as the contests in Maine, Michigan, and Texas, where left-wing Democratic candidates have driven national headlines by donning Nazi tattoos, refusing to celebrate the death of the ayatollah, and calling God nonbinary. But the Republican frontrunner in the Granite State, John Sununu, doesn't seem to mind flying under the radar—at least for now. "You have lots of politicians