The worrisome split screen told the story: On one side, college campuses shut down for the semester, the National Guard deployed to create a “containment zone” in New York, and major employers instructed their workforce to telecommute. On the other, massive lines wound through precincts across Michigan and North Dakota, with Democratic voters standing nearly on top of each other, often for hours, before approaching volunteer poll workers protected only by Purell. At the same time that large gatherings were canceled, states of emergency were declared, and public institutions were dusting off catastrophe plans, the queues stretched through community centers, campuses and town halls — and 30 more primaries have yet to be conducted. The coronavirus pandemic presents an entirely new challenge for America’s electoral system: how to ensure that all citizens can exercise their right to vote without jeopardizing public health in the process. One common-sense measure would be to dramatically expand vote-by-mail options, allowing citizens to cast their ballots from a safe distance. (While every state allows voting by mail under some conditions, only five states conduct all of their statewide elections in this manner.) On Wednesday, Sen. Ron Wyden (D-Ore.), whose state pioneered vote by mail in the 1990s, introduced legislation that would provide $500 million for states to begin making contingency plans for November’s election. If a state hard hit by coronavirus does need to transfer to a large-scale vote-by-mail operation, it would take months to buy optical scanners, put them in place and retrain poll workers. The transition requires a lot of extra preparation: The long delays counting the primary vote in California and Michigan, which have recently expanded early and absentee voting, have already shown that the system is often unprepared for tallying large numbers of pre-Election Day ballots.