The GOP presidential race veered offshore to Puerto Rico, where 20 delegates were in stake in Sunday's primary but residents cannot vote in the general election. While fighting for votes in the U.S. territory, Mitt Romney and Rick Santorum already shifted their focus to upcoming primaries in Illinois and Louisiana. Front-runner Romney held a sizable edge in delegates, cash and campaign organization, but Santorum hoped for a drawn-out nomination fight through the summer that would deny Romney the clincher and set up a contested party convention in August. "One of the great blessings I've had in every political campaign is people underestimate me, people underestimate what God can do," Santorum told a church audience in Louisiana. Romney and Santorum criticized the other from afar as they looked ahead to Tuesday's primary in Illinois and Louisiana's contest on Saturday. GOP rivals Newt Gingrich and Ron Paul both remained in contention, too, but seemed overshadowed by the Romney-Santorum rivalry. "This is a primary process where somebody had a huge advantage, huge money advantage, huge advantage of establishment support and he hasn't been able to close the deal and even come close to closing the deal," Santorum said of Romney. That tells you that there's a real flaw there. Santorum faces his own flaws. He badly trails Romney in fundraising. His organization is a shadow of Romney's and his advertising a fraction of what's airing in support of the former Massachusetts governor. "In a campaign, one of the things you recognize from Day One is that you need to organize a financial operation to make sure you can run the campaign," Romney said. We have to have a nominee who has the capacity and the organization necessary to raise money to be competitive. I intend to be very competitive with President Obama, to make sure that we get our message out, we defeat him. This is not about a shoestring operation," Romney said. The latest test was Puerto Rico, where 20 delegates were up for grabs in the race for the 1,144 delegates needed to win the nomination and face President Barack Obama in the general election. As the day began, Romney had 501 delegates in his camp and Santorum had 253, according to The Associated Press' tally. Gingrich trailed with 136 delegates and Paul had 50. "Why, with tens and hundreds of millions of dollars, hasn't he been able to do anything to get this nomination even close to cemented away?" asked Santorum, a former senator from Pennsylvania. Romney is on pace to capture the nomination in June. Both say they would try to force the nomination to a fight in Tampa and turn the convention into more than a glossy advertisement for the party for the first time since 1976. Romney's aides said that was a fantasy scenario, but they are working hard to prevent it. "I can't tell you exactly how the process is going to work," Romney said. But I bet I'm going to become the nominee, I sure hope I'm going to become the nominee. With half the states yet to weigh in on the Republican presidential nomination, the question of how likely some serious delegate trading would go on at the national convention in Tampa is being asked more frequently. Republican National Chairman Reince Priebus insisted that his party will have a nominee sooner rather than later.