OutofDate1980
Android Expert
In that case you'd just cast a provisional ballot. After the fact they'd verify you were who you say you were and your vote would count. Same thing as if you show up at the poll and you haven't registered to vote.
Provisional ballot - Wikipedia, the free encyclopedia
In the 2004 US Presidential Election, controversy arose out of arguments regarding the interpretation of the criteria for determining the eligibility of voters using provisional ballots. Many allege that these discrepancies of interpretations, particularly in Ohio, may have been a deciding factor in the outcome of the election. In the 2004 election, at least 1.9 million provisional ballots were cast, and 676,000 were never counted due to various states' rules on counting provisional ballots.[5]
Studies of the use of provisional ballots in the 2006 general election in the United States show that around 21% of provisional ballots were rejected, where the majority of rejected ballots were cast by registered voters and the majority of rejections were for reasons that were preventable.[6]