According to a recent WSJ/NBC News/Marist poll of likely Illinois voters, Vermont Sen. Bernie Sanders is gaining ground on Democratic frontrunner Hillary Clinton, while billionaire Donald Trump holds a strong lead over his Republican counterparts.
Clinton, an Illinois native, leads Sanders 51 percent to 45 percent in Illinois.
The two Democratic presidential candidates have both campaigned heavily in the state.
Sanders opened a Chicago campaign office in February and hosted a rally at Chicago State University later that month. He also held a campaign event in suburban Summit last week. Sanders is set to hold a rally Monday night at Chicago's Auditorium Theater.
Clinton opened two Chicago campaign offices in February. Last week, her husband, former President Bill Clinton, stumped for her in Evanston and Peoria. Clinton addressed the Plumbers Jac Local Union 130 UA in Chicago Monday.
Clinton currently leads Sanders in pledged delegates, 766 to 551.
In Illinois' winner-take-most primary, 182 Democratic delegates are up for grabs.
On the Republican ticket, Trump garnered 34 percent of support, with Texas Sen. Ted Cruz receiving 25 percent, Ohio Gov. John Kasich receiving 21 percent and Florida Sen. Marco Rubio receiving 16 percent.
Trump postponed a Chicago rally Friday, citing safety concerns, after thousands of protesters descended on the event to protest the Republican frontrunner's candidacy. He recently replaced his Illinois campaign director as a result of an alleged lack of organization. Trump held a campaign rally at Bloomington's Synergy Flight Center Sunday.
Cruz's wife, Heidi Cruz, addressed a City Club of Chicago breakfast last Wednesday. The Texas senator also attended the Northwest Suburban Republican Lincoln Day Dinner last Friday.
Kasich appeared at a town hall event at a truck manufacturing company in suburban Lisle last Wednesday. He also held a Town Hall at Palatine's Park District Community Center that same day. Kasich's home state of Ohio will also be decided Tuesday.
Rubio has had no commitments in Illinois, although Conservative Solutions PAC, a super political action committee backing the senator, has spent over a half-million dollars on anti-Trump ads in the state. Rubio's home state of Florida will also be decided Tuesday.
Trump currently leads the Republican field with 460 pledged delegates. Cruz holds 369 pledged delegates, while Rubio holds 163 and Kasich holds 63.
Sixty-nine Republican delegates are up for grabs in Illinois' winner-take-most primary. The vote is two-pronged, so even if Trump wins Illinois' presidential preference vote, Cruz, Kasich and Rubio still have an opportunity to score delegates.
The survey was composed of 529 likely Democratic voters and 421 likely Republican voters. The margin of error was plus or minus 4.3 points and 4.8 points, respectively.