WASHINGTON — The demand for mail-in ballots is surging. Election workers need training. And polling booths might have to be outfitted with protective shields during the COVID-19 pandemic. As officials prepare for the Nov. 3 election, one certainty is clear: It’s coming with a big price tag. “Election officials don’t have nearly the resources to make the preparations and changes they need to make to run an election in a pandemic,” said Wendy Weiser, head of the Brennan Center for Justice’s democracy program.