The first polling sites opened at 6 a.m. EST Tuesday in a handful of states — Connecticut, Indiana, Kentucky, Louisiana, Maine, Missouri, New Jersey, New York and Virginia.
Heavy rains and flash flooding in a swath of the Southwest were expected to make it harder for some voters to reach polling places in parts of Colorado, Arizona, Utah and New Mexico. Election administrators in the Navajo Nation announced changes to several of its polling locations, and in Utah's rural San Juan County, voters were being allowed to vote electronically on Tuesday because some of them may not be able to reach polling places.
Election administrators and voting rights advocates have been advising voters casting late absentee ballots to use drop boxes or deliver them to polling places in person rather than mail them.