A poll or two is predicting a close race between Rick Santorum (R.PA) and Mitt Romney (R.MA) in the Illinois primary, set to take place on March 20th. Santorum, for his part, doesn’t seem to enthusiastically believe those polls. Santorum understands what type of voter he appeals to, a type that does not represent the majority of Illinoisans–rural Americans.

While responding to a reporter’s question about how well he thinks he will do in the Illinois primary, Santorum stated that he didn’t really know how well he would do considering how large of an urban population the state has. Illinois is only about 13 percent rural.

On March 13th Santorum won primaries in Mississippi and Alabama. Mississippi is 55 percent rural while Alabama is almost 30 percent rural. Newt Gingrich took second place in both primaries; Mitt Romney had a lackluster 3rd place finish in both races.

While Mitt Romney has his weaknesses, namely that many Republican’s don’t seem to think he’s a ‘real conservative’–and don’t hesitate to publicly say so–Santorum’s weakness is demographics. The people who Santorum most appeals to do not represent a majority of America. Rick isn’t the only one to notice that outside of the rural areas his support wanes. Joel Kotkin describes where Santorum is widely supported and where Romney has the advantage:

If America was an exclusively urban or metropolitan country, Mitt Romney would be already ensconced as the GOP nominee and perhaps on his way towards a real shot at the White House. In virtually every major urban region — which means predominately suburbs — Romney has generally won easily. Mike Barone, arguably America’s most knowledgeable political analyst, observes that the cool, collected, educated Mitt does very well in affluent suburbs, confronting President Obama with a serious challenge in one of his electoral sweet spots.

Outside the Mormon belt from Arizona to Wyoming, however, sophisticated Mitt has been a consistent loser in the countryside. This divergence between rural and suburban/metro America, poses a fundamental challenge to the modern Republican Party. Rural America constitutes barely 16 percent of the country, down from 72 percent a century ago, but still constitutes the party’s most reliable geographic base.

Perhaps if Romney and Santorum got together on the same ticket they might have a chance of beating Obama; it could happen. Obama put old disagreements aside and chose Joe Biden as his Vice-President and Hillary Clinton as Secretary of State.

Getting the vote of rural America alone does not a president make. Until (or unless) Santorum can appeal to a large swathe of Americans who don’t live in the country or on farms, the Republicans are still just biding time until Romney receives the Republican nomination for president.