As voters in 23 states head to polls or caucuses today to pick their party’s presidential candidate, local election officials around the country are bracing for a long, exhausting night and an array of unpredictable factors that might prevent some states from reporting final tallies until early Wednesday morning. Although no one is predicting serious problems, many voting officials acknowledge that they could happen.

Isolated problems were already cropping up as polls opened this morning.

In New Jersey Governor Jon Corzine was scheduled to vote shortly after 6 a.m. when his polling station in Hoboken opened, but he had to wait for nearly an hour because two of the voting machines were not working properly. One machine was fixed after 45 minutes, but about a dozen voters were turned away in the meantime. Voting officials there also did not have provisional ballots on hand as a backup. By 7:15 a.m., the governor was able to cast his ballot.

A spokeswoman for Sequoia Voting Systems, the maker of the machines used at the polling station, said that the problem was caused by errors made by poll workers, not by a machine malfunction.

Several states are expecting a higher than usual turnout, which could increase bottlenecks in precincts with too few voting machines. The growing popularity of absentee voting is also contributing to possible delays because the ballots take more time to process and often arrive at the last minute.