Some might have initially questioned U.S. Sen. Mark Kirk's December prediction that "Illinois will be relevant" come March 20.
After all, Illinois' presidential primary has traditionally been held so late in the game that leading presidential candidates had already sewn up the number of delegates needed for nomination.
But this time around, with no clear Republican victor and a knockout punch from this week's Super Tuesday contests uncertain, Illinois will have the national spotlight as the lone primary the third Tuesday of March, with the suburbs expected to be prime territory in the battle for Republican presidential delegates.
"You're probably going to have a suburban contest," said Paul Green, political science professor at Roosevelt University. "You fish where the fish are."
A total of 54 delegates and 54 alternates -- divided among the state's 18 congressional districts -- will be directly elected by voters pulling Republican ballots.
Twenty-one of them are from the Northwest and West suburbs, traditional Republican strongholds. Another 15 delegates will be chosen at the Illinois Republican convention in June, for a total of 69 delegates at stake -- one of the highest in primaries across the country.
Of the four remaining members of the once-packed primary field, former Massachusetts Gov. Mitt Romney, Texas Rep. Ron Paul and former House Speaker Newt Gingrich of Georgia have all filed full slates of delegates in Illinois. Former Pennsylvania Sen. Rick Santorum's campaign filed for delegates in 14 of 18 districts, excluding traditional Democratic strongholds in Chicago.
The Romney campaign in Illinois carries both the benefit of organization and manpower, with state Treasurer Dan Rutherford serving as chairman.
Green says Romney will be looking for independent, swing votes in the suburbs, especially among women, who may disagree with the conservative social policies of Santorum.
Republican Congressman Aaron Schock of Peoria, an early Romney backer, reiterated the campaign's focus on the economy.
"When you have unemployment over 8 percent for over 40 months, it behooves you to talk about issues that are front and center," said Schock. "For social conservatives and social moderates, (the primary question) is, how do we get the economy out of the rut we're in?"
Santorum's Illinois political director, Jon Zahm, formerly of Batavia, said he expects the campaign to do well in towns on the Missouri and Iowa borders, but he also sees the suburbs as a stronghold. Santorum's headquarters is in Elgin, which is in three congressional districts.
"Some of our highest levels of volunteers are from Elgin and nearby," Zahm said.
While the campaign initially faced both organizational and money hurdles, struggling to afford basic aspects of campaigning, Zahm said the Illinois campaign has grown from about a dozen volunteers at the start of the new year to more than 250 volunteers. He describes the campaign as "bottom up" with a grass-roots focus and the help of Tea Party groups and anti-abortion groups.
Gingrich's campaign is being run by Barrington resident Keith Hanson, a longtime friend of the former speaker. Hanson said the Gingrich national office has a "high degree of confidence" in the amount of support for the former House speaker in southern and central Illinois.
"It's a lot harder to gauge things up here," Hanson said. "I don't want to say people have a shorter attention span but it seems (their opinions) are more likely to be changeable."
The Gingrich campaign says much of its support lies in suburban Tea Party groups, but concedes those numbers can be hard to gauge.
Gingrich plans visits to Illinois the week before the primary, spending most of that time in the suburbs, meeting with local officials, delegates and perhaps a local school, Hanson said.
Schock said Romney is expected in Peoria the day before the primary and plans to spend a portion of election night in the suburbs. Zahm said Santorum has not yet finalized election night plans. Suburban leaders in Paul's campaign did not immediately return calls.
Because voters' choices for the presidential candidate and presidential delegates are technically unrelated, the presidential portion of the Illinois primary ticket is considered by analysts to be a "beauty contest." But Roosevelt's Green points out that "most who vote for the delegates of one guy aren't going to jump in the beauty contest for the other guy."
Romney has 150 total delegates, Santorum has 85, Gingrich has 29 and Paul has 18, according to The Associated Press. A candidate needs 1,144 delegates to win the Republican nomination.