Scattered voting problems, including machine glitches and long lines, emerged in some states on the biggest Super Tuesday ever held in America. But overall, voting appeared to go smoothly.
A record turnout was expected as an unprecedented 24 states held primaries and caucuses to narrow the field for the Democratic and Republican presidential nominee.
Eight precincts in Chicago had minor problems and a ninth was expected to stay open for several extra hours after misplaced voting equipment caused a nearly two-hour delay in opening the polls.
Cook County Clerk David Orr said no major problems had been reported. "We had other calls that the polls were slow, one precinct opened at 6:15 (instead of 6 a.m.), and another where they were missing a certain kind of ballot ... but we don't think we lost any voters," he said.
At a Chicago hot dog joint doubling as a polling place, a technical glitch left only one touch-screen machine in use, making the line to vote much longer than the queue at U Lucky Dawg's counter, where the specials of the day included a Flying Mario Burrito for $3.09.
In Georgia, where voters are now required to present photo identification, wait times in some areas were as long as 90 minutes because for the first time in a major election, poll workers had to compare IDs against computerized registration records.
A spokeswoman for Democratic hopeful Barack Obama said the campaign was considering asking Georgia officials to keep at least one Atlanta precinct open late because it didn't open on time. Heavy turnout and sporadic computer problems may prompt additional requests for extended poll hours, said Obama spokeswoman Adora Andy.
"That (comparison) process with the computer terminals is very slow, and that can create some long lines," said Clare Schexnyder of Election Protection, a national election monitoring group. "We're finally figuring out that it's not that there are not enough voting machines, it's the check-in process."
By its nature, electronic voting is prone to both manmade and technical glitches.
"Voting machines are always going to have issues. That's inevitable," said Tova Wang of The Century Foundation think tank. "They're machines that are operated by human beings. The question is whether the poll workers are trained and have everything they need. If the machines malfunction, do they have paper ballots and do they have enough of them?"
Weather was a concern in some states. Snow or rain fell in states including Connecticut, Illinois, Kansas and Massachusetts, and elections officials worried that might discourage some voters. In Tennessee, where temperatures were in the 70s, a storm front threatened to bring hail and tornadoes.
Some Tennessee school districts, including Memphis, announced early closings so students could get home before the expected bad weather. Polls were still scheduled to remain open statewide until 8 p.m. EST.
"I would encourage voters, if they can go ahead and vote -- vote," said state Election Coordinator Brook Thompson. He urged local election officials to keep up with weather forecasts and conditions in their counties.
In Arizona, where voting activists feared a controversial photo ID rule could cause confusion, things were apparently fine. "People are walking up to the polls with their drivers' licenses in their hands," said Mindy Moretti, who was monitoring voting in the Phoenix and Scottsdale areas for the watchdog group Electiononline.org. "People seem ready for it. No one seems to be upset."
In the lead-up to Super Tuesday, voting advocates worried that long lines, high turnout and record numbers of mail-in ballots in states such as California could drag out the counting process for days. Across the country, election officials have estimated that mail-in ballots may account for as much as 50 percent of the vote in some areas.
More than 5 million people have requested mail-in ballots in California, where there are 15.7 million registered voters. Election officials in the most populated and delegate-rich state in the country have said results may not be available until Wednesday or later.
As much as 25 percent of the overall vote may go uncounted Tuesday night, officials said. A major cause of expected delays is late-arriving mail-in ballots, which will be counted only after precinct votes are tallied. Polls close at 8 p.m. PST.
Another element is the state's recent switch from electronic voting machines to paper ballots. Four of California's most populous counties -- Riverside, San Bernardino, San Diego and Santa Clara -- must count votes at centralized locations because there aren't enough optical scanners for every precinct. Los Angeles and Sacramento will also haul their paper ballots to a single location, where they will be tallied electronically.
"We're working as late as we can to get all of them counted," said San Bernardino registrar Kathi Payne.