CHICAGO (CBS) — Polls are open across Illinois as voters cast their ballots in the races for governor, other statewide offices, Congress, the Illinois General Assembly, and many county races.

Crowds were already lined up at several polling places before 6 a.m., and if early voting numbers across Illinois are any indication, voters could see large crowds at the polls on Tuesday.

More than 271,000 people voted early in the Cook County suburbs this year, a 112 percent increase from the last midterm election in 2014. In Chicago, early voting was up 96 percent from 2014, with roughly 224,000 ballots cast, about half of them in the past six days.

At the Loop supersite, long lines were the order of the day on the last day of early voting on Monday, with people waiting as long as two hours to use the 80 voting machines set up at 175 W. Washington St. At times, the line stretched down Washington, and around the corner onto LaSalle Street.

“The early voting numbers I gave you for this gubernatorial election beat the presidential elections of ’08 and ’12. We’re probably not going to beat 2016, but that’s still extraordinary the turnout numbers there,” said Cook County Clerk David Orr.

Chicago election officials reported a handful of polling places opening late on Election Day, largely due to delays in setting up voting equipment.

“Hopefully no voters are inconvenienced,” Chicago Board of Election Commissioners spokesman Jim Allen said. “With 2,000 precincts, we’ll unfortunately have a couple like this.”

If any voters were unable to vote due to the delays, and cannot make it back to their polling place before the scheduled 7 p.m. opening, election officials can seek a court order to keep the polling place open late.

In addition, in Porter County, Indiana, six polling places opened late, because some poll workers did not show up. Some precincts had only two poll workers. Porter County Election Board officials said some polling places remain understaffed, but open, and voters are being asked to be patient.

The midterm elections come two years after Russia tried to hack into Illinois voting systems during the 2016 elections. With razor-thin margins of victory expected in several races, there are concerns about fraud and cyber security.

“Let’s say the worst happens. We certainly hope it doesn’t. We’re ready for hopefully anything. But we could recreate the entire election,” Orr said.

The Illinois Attorney General’s office has announced 187 teams of election monitors will fan out across the state to guard against fraud, and to make sure voter rights are protected.

The U.S. Attorney’s office also will conduct Election Day monitoring, with a hotline available for people to report complaints at 312-469-6157.

Voters are not required to show ID to vote. If you still need to register, however, you need two forms of identification, including at least one that shows your current address.