On the morning of the primary here in August, the local elections board met to decide which absentee ballots to count. It was not an easy job. The board tossed out some ballots because they arrived without the signature required on the outside of the return envelope. It rejected one that said “see inside” where the signature should have been. And it debated what to do with ballots in which the signature on the envelope did not quite match the one in the county’s files. “This ‘r’ is not like that ‘r,’ ” Judge Augustus D. Aikens Jr. said, suggesting that a ballot should be rejected. Ion Sancho, the elections supervisor here, disagreed. “This ‘k’ is like that ‘k,’ ” he replied, and he persuaded his colleagues to count the vote. Scenes like this will play out in many elections next month, because Florida and other states are swiftly moving from voting at a polling place toward voting by mail. In the last general election in Florida, in 2010, 23 percent of voters cast absentee ballots, up from 15 percent in the midterm election four years before. Nationwide, the use of absentee ballots and other forms of voting by mail has more than tripled since 1980 and now accounts for almost 20 percent of all votes.
Yet votes cast by mail are less likely to be counted, more likely to be compromised and more likely to be contested than those cast in a voting booth, statistics show. Election officials reject almost 2 percent of ballots cast by mail, double the rate for in-person voting. “The more people you force to vote by mail,” Mr. Sancho said, “the more invalid ballots you will generate.”
Election experts say the challenges created by mailed ballots could well affect outcomes this fall and beyond. If the contests next month are close enough to be within what election lawyers call the margin of litigation, the grounds on which they will be fought will not be hanging chads but ballots cast away from the voting booth.