Election officials in Florida were forced on Thursday to reissue thousands of absentee ballots following complaints from voters who said they had asked for the ballots but not received them.
The turmoil in Florida was the latest sign that next Tuesday's vote may be marred by irregularities at the polls.
Democrats and Republicans, as well as non-partisan groups, plan to send lawyers to monitor voting across the country. The US Justice Department plans to send more than 1,000 observers three times the number dispatched four years ago.
Even before election day, lawsuits across the country are shaping the rules to be used.
A federal judge in Ohio has scheduled a hearing for on Friday on Republican challenges to about 35,000 voter registrations. Republicans in Ohio say that because mail addressed to the new registrants came back undelivered, the registrations could be fraudulent.
But Democrats say the challenges are a partisan attempt to keep voters including thousands registered by groups supporting John Kerry away from the polls.
Meanwhile, courts are still wrestling with how to handle “provisional ballots”. The ballots, required for the first time this year, are to be used when voters say they are properly registered but their names do not appear on the rolls. The votes are counted later, if officials determine that the voter's registration is valid.
In Michigan, a federal court ruled this week that provisional ballots cast outside the precinct where a voter lives could not be counted. A three-judge panel has vowed to hear an appeal against that ruling. In Florida, state law enforcement officials said they had found no evidence of criminal wrongdoing in their investigation of missing ballots. Brenda Snipes, Broward County's elections supervisor, said she would send duplicate ballots to registered voters who had not yet returned their absentee ballots.
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