Romney redoubles effort in Ill. after last week's losses to Santorum Still heavily favored to win Illinois, the former Massachusetts governor nonetheless tore up his schedule and cut short a campaign trip to Puerto Rico, which holds its primary Sunday, to devote extra days to a contest that he hopes will restore his momentum in the battle for the nomination. Though Chicago and its suburbs will cast a majority of the votes Tuesday, the smaller towns far from the city drew the leading Republican candidates Saturday. Romney's greatest strength will be in the Chicago area, where Republicans are fiscally conservative but more moderate on social issues. In downstate Illinois, particularly where Santorum campaigned on Saturday, the population is sparser, but the former Pennsylvania senator's social conservatism and moral passion are likely to find considerable support there. Santorum scheduled three stops in central and southern Illinois, while Romney's town hall was across the Mississippi River from St. Louis. At a mid-afternoon rally in Effingham, Santorum drew a crowd approaching a thousand people. He lashed out at Romney, calling him a moderate who would not be able to draw a sharp contrast with President Obama in the general election. As a voice from the audience cried out "Down with Obama," Santorum pressed his argument that Republicans should not nominate someone "who agrees with that horrible record" of the president. As he does at nearly every stop, Santorum attacked Romney for enacting a health-care plan in Massachusetts that he said was a model for the law Obama championed and signed as president. "We need someone who can go out and take President Obama on," Santorum said. Santorum said that if voters deliver him a victory Tuesday, "I guarantee you that we will win this nomination. We will nominate a conservative, and if we nominate a conservative, we will beat Obama. But as if to hedge his bets, Santorum planned to leave the state Sunday to campaign in Louisiana, where Saturday's primary may offer him a chance to rebound if he loses Illinois on Tuesday. Romney's closest rival campaigned in the Chicago suburbs Friday, then made a brief detour to Missouri on Saturday, where Republicans were holding their precinct caucuses. The caucuses are the first of several steps in a process of picking their delegates to the national convention. There were no immediate results from Missouri. Santorum won the state's beauty contest primary Feb. 7, one of three victories that night that catapulted him into the top ranks of the GOP race. But Romney's campaign is focused on winning more delegates once the process there is completed. Romney's stepped-up efforts in Illinois also include harsh new negative advertising. As in all other states with competitive races, Romney and a super PAC are heavily outspending Santorum. Santorum joked with audiences this weekend about the automated telephone calls Romney's campaign is beaming into Illinois households. Asking for campaign donations, he pledged not to spend the money on the so-called robocalls. Romney's advisers have expressed little concern that he could lose the state's primary - which would have a devastating impact on his candidacy - but Romney is doubling down to grind out as big a win as possible. Romney typically keeps a light campaign schedule on Sundays or takes the day off, but is scheduled to make three stops across Illinois this Sunday. He is planning to travel the state again Monday before holding an election night party Tuesday in the Chicago suburbs. While Romney is the favorite in Illinois, he and his aides have tried to keep expectations in check. Asked Saturday to assess his chances, Romney told reporters: "You know, I hope that we're going to do well there as well, but I'm going to be there this afternoon, so we'll see." Ron Kaufman, a senior adviser traveling with Romney in Puerto Rico, said of the campaign's confidence heading into Illinois: "This is not a cycle for confidence. This is a cycle for hard work.