I’m getting this question a lot today and I haven’t spent time researching this question.  So let me send people to the two best articles on this I know of:

Jerry Goldfeder, Could Terrorists Derail Our Presidential Elections?

Maya Roy, The State of Democracy after Disaster: How to Maintain the Right to Vote for Displaced Citizens

I very much hope for the sake of the people in the Northeast that we will not have to delve into these issues over the next few days.