https://arstechnica.com/tech-policy/2018/11/are-elections-fixed-no-but-neither-is-election-security/

As those of you reading this from the US (hopefully) vote today, in all likelihood your vote will be counted correctly and you won't be turned away from the polls because someone hacked the voter registration data. Yet for a small but non-zero minority, something will go wrong that will stand in the way of their ability to cast a vote for the candidate of their choice. It could be a glitch in a voting machine interface that wasn't caught before they commit their ballot, voter registration data that has been flagged as incorrect or has been purged, or maybe a targeted robo-call that gives them bad information about the election.