EFFINGHAM, Illinois (Reuters) - In Tuesday's Republican primary in Illinois, most votes will be cast in the suburbs and towns ringing Chicago, but Rick Santorum has his eye elsewhere.
Despite needing a win to slow Mitt Romney's trudge toward the nomination, Santorum has campaigned largely in rural parts of Illinois, where, he said, "the heartland really begins."
For Santorum, scouring for votes in conservative farming areas is the same tactic that helped him squeeze out a victory in the Iowa caucuses, although it has not served him well in the rest of the Midwest.
His main rival Romney is not winning the hearts of conservatives in the hinterland but the former Massachusetts governor's messages on the economy and more moderate stance on social issues resonate better in and around big cities.
"You know you don't get a chance to out-vote your friends up in the Chicagoland area very often, but this is your primary," Santorum said on Saturday, in a warehouse full of butcher blocks 200 miles south of Chicago in Effingham, home to 12,000 people.
Not far away, a 200-foot cross stands beside the intersection of two major highways, a symbol of locals' deep religious faith which Santorum says he shares.
During a campaign stop in Missouri last weekend, the former senator from Pennsylvania praised his supporters for sticking to their values, and contrasted their lifestyles with that of cosmopolitan types on the coasts.
"I kept saying, you just stick with us, you go out and vote for your values and trust what you know," Santorum said. "Because you don't live in New York City. You don't live in Los Angeles. You live like most Americans in between those two cities, and you know the values you believe in."
By and large, Republican voters have split between the two rivals along urban and rural lines in recent state contests to win the Republican nomination to challenge President Barack Obama in the November 6 elections.
In Alabama, where Santorum won the primary last week, he lost only four counties to Romney, all of them in metropolitan areas like Birmingham and Montgomery. In Ohio, where Romney won by a thin margin, his victories in counties including the cities of Cleveland, Columbus and Cincinnati made the difference.
Illinois appears to be taking a similar form. According to a recent Chicago Tribune poll, Romney led Santorum 39 percent to 30 percent in Cook County, which includes Chicago and some of the surrounding suburbs. It also where the majority of the state's Republicans reside. Santorum outpolled Romney 35 percent to 29 percent in the 96 counties outside the Chicago area.
An opinion poll on Monday put Romney well ahead of Santorum by 45 percent to 30 percent in Illinois, a bastion of Democratic support and home to Obama's campaign headquarters.
"You can't say you are going to beat Obama and never win a city or a suburb," said Keith Nahigian, who managed the presidential campaign of Michele Bachmann, a congresswoman from Minnesota. "If you are not connecting with the major population centers, you are not going to be the nominee."
Santorum graduated from high school not far from Chicago and now lives in a Washington bedroom community in northern Virginia but his social values connect well with rural conservatives. He also comes across as less polished than former private equity executive Romney.
"In the early debates, Rick Santorum came off a little agitated," said Marla Galloway, a 43-year-old voiceover performer from Newton, Illinois. "He was saying, 'What about me?' That's also what's cool about him. I think people here are a little agitated. We also feel overlooked."
Santorum played the underdog on a stop in Arlington Heights, 25 miles from Chicago, one of his few Illinois events in the Chicago area.
"No one, no one is expecting us to do well here in Illinois," he said. "We're being outspent ten to one. And it's a state, they say, 'Well, it just fits Romney. It's a moderate Republican state.' Conservatives don't have much of an opportunity in Illinois to speak their voice."
Santorum aides insist that his appeal extends beyond deep-red, rural districts and point out that Santorum won statewide Senate races in Pennsylvania where Democrats greatly outnumbered Republicans.
"What in Mitt Romney's background has he ever shown that he has the ability to win elections in the states we are going to need to win in?" said Santorum spokesman Hogan Gidley.
On radio stations in Illinois this weekend, the Romney campaign reminded voters of Santorum's failure in Pennsylvania, when the senator lost his seat in 2006 by historic margins.
The spot, playing more than once an hour on one station, includes a newscaster recounting how poorly Santorum fared.
"He lost across the board with voters - among Democrats and independents, women and men, blacks and whites, young and old, rich and poor," the ad says.
Gidley said that the campaign would win over so-called Reagan blue-collar Democrats, conservative voters who switched from the Democratic Party to support Ronald Reagan in 1980.
But Romney has beaten Santorum in places where Reagan Democrats are traditionally found, winning more votes in small industrial cities like Davenport, Iowa; Saginaw, Michigan; and Dayton, Ohio.
The split between urban and rural counties is playing out nationwide as the majority of Romney's victories have come in blue states, traditionally Democratic strong holds, many home to big cities.
Romney has won 15 state contests. Obama won nearly three-quarters of those states in the general election four years ago. Seven of those states, the Democrat clinched by more than 10 percentage points on Election Day.
Santorum by contrast, has been winning where Arizona Senator John McCain, the party's nominee in 2008, was most successful. Of the ten states Santorum has won, seven were claimed by McCain in the last election.
The Santorum campaign says its success in red states is a sign of the campaign's durability and the authenticity of its candidate. But with Romney winning in key swing states like Ohio and Florida, analysts say he is showing himself to be a more formidable candidate for the fall.
"It means Romney's a better general election candidate," said Quinnipiac University pollster Peter Brown. "This whole election is not about the states that John McCain carried. It's about how many of the states that Barack Obama carried last time the Republicans take from him."
Editing by Alistair Bell and Anthony Boadle