A substantial portion of Illinois voters cast early ballots ahead of Tuesday's primary election, breaking records in Chicago.
As of 3:45 p.m. Sunday, 129,957 early votes had been cast in Chicago, according to James Allen of the Chicago Board of Elections, shattering records for a primary election in the city.
The previous record was set during the 2008 primary election when 81,690 early ballots were cast. In that election, President Barack Obama and Arizona Senator John McCain won the state's Democratic and Republican primaries, respectively.
Obama and McCain ultimately faced off in the 2008 general election.
A total of 51 early voting sites have been open in Chicago since the end of February, but only 14 "permanent locations" are accepting early ballots Monday.
In the Cook County suburbs, 102,409 early ballots were cast by Sunday afternoon. Compare this to the 51,116 early votes cast in suburban Cook County for the 2008 primary.
In addition to this, a record number of 1,443,261 Illinoisans have registered to vote for Tuesday's primary, according to Cook County Clerk David Orr.
No-excuse early voting was instituted in Illinois in 2006 as a means to combat declining voter turnout.
This year, Democrats have accounted for 90 percent of early voting in Chicago, with Republicans accounting for 10 percent. In 2008, voter turnout was 93 percent Democrat and 6 percent Republican. In 2012, Democrats accounted for 81 percent of early votes, while Republicans accounted for 18 percent.
In suburban Cook County, Democratic voters have accounted for 72 percent of early voting, while Republicans have accounted for 29 percent. In 2008, 80 percent of early voting was Democratic, while 19 percent was Republican. In 2012, Democrats accounted for 61 percent of early voting, while Republicans accounted for 39 percent.
Former Secretary of State Hillary Clinton will face Vermont Sen. Bernie Sanders on the Democratic ballot, while billionaire Donald Trump will face Texas Sen. Ted Cruz, Florida Sen. Marco Rubio and Ohio Gov. John Kasich on the Republican ballot.
The race for Mark Kirk's U.S. Senate seat will also be hotly contested.
Kirk faces Oswego businessman and political newcomer James Kirk in the Republican primary. Rep. Tammy Duckworth faces Urban League President and CEO Andrea Zopp as well as state Sen. Napoleon Harris in the Democratic primary.
Embattled Cook County State's Attorney Anita Alvarez also faces a formidable challenge in Tuesday's primary. She will face former Assistant State's Attorney Kim Foxx as well as former state and federal prosecutor Donna More in the Democratic primary.
Christopher Pfannkuche is running unopposed on the Republican ticket.
Visit the Illinois Board of Elections website to register to vote and find polling locations.