EFFINGHAM, Ill. - Rick Santorum suggested that campaigning against Mitt Romney for the Republican nomination is merely a warm-up act to running against President Obama in the general election because, in his view, the two support similar policy positions.

"People ask me why I'm the best candidate to run against Barack Obama. It's because I feel like, in many respects, I am running against Barack Obama here in this primary because Mitt Romney has the same positions as Barack Obama," Santorum said today at an afternoon rally at a warehouse in southern Illinois.

Santorum often ties Romney to Obama based on their healthcare plans and positions on carbon emissions, but picking up the attacks on Romney today, Santorum added a new link between the Massachusetts governor and the president based on their stance on fossil fuels.

"Why, with sky rocketing gas prices, would we nominate someone who had the same position as President Obama with respect to fossil fuels? Why would we give that issue away in this election?" he asked.

Santorum also took issue with Romney's alleged inability to directly address the problems of Obama's healthcare plan because it was crafted from the same foundation as the healthcare plan he implemented in Massachusetts.

"How long does he talk about Obamacare and the fact that he'll repeal it? Oh he puts out that one liner. But does he really get into the core issues? No. Because he can't," Santorum said.

In response to Santorum's attacks on Romney, a spokesman for Romney said voters should be concerned that Santorum possesess no experience in job creation.

"Senator Santorum is an economic lightweight who has precisely zero job creating experience. He ought to scare every conservative when it comes to his economic record. We won't get  the economy going again by replacing one Senator with no job creating experience with another with no job creating experience," said Ryan Williams, spokesman for Romney's campaign.

On the ropeline following his event, Santorum attempted to clarify his comment from earlier in the day when he wrongly claimed he'd won all the states in the Midwest, despite losing Michigan and Ohio to Romney in February.

"Well, I meant the heartland," Santorum said, although many consider Ohio to be a part of the heartland.

The former Pennsylvania Senator, who lived in the Chicago area during his senior year of high school, was optimistic that a win in Illinois Tuesday would help him secure the nomination.

"I think that's going to be a ticket for us to go. We'd feel very very good about, let's put it that way. Really good about it," said Santorum.

Before his stop at Effingham, Santorum, who donned a green flower on his coat jacket lapel, admitted he squeezed in some time to celebrate St. Patrick's Day at an Irish pub with typical Irish fare - corned beef and a pint of Guinness.

"I usually get there in the morning so I felt a little bad I didn't get there until lunch time," he said. "I had some corn beef and of course a Guinness."