The coronavirus pandemic is forcing millions of American voters worried about their health to scramble to vote by mail for the first time. But a requirement in a handful of states, including presidential battleground North Carolina and Wisconsin, that a witness or notary public sign a ballot envelope is tripping up some voters early. That’s worrying voting rights advocates weeks before an unprecedented election. The requirement contrasts with the five all-mail voting states in the West where there's no such witness mandate. The requirement has been the focus of litigation in Wisconsin, North Carolina and other states this year.