SAN JUAN, Puerto Rico - It's supposed to rain in Puerto Rico this weekend, but Mitt Romney isn't leaving because of the weather.
Romney, campaigning for Sunday's Republican presidential primary in this U.S. territory, had initially planned to stay here until Sunday before heading to Illinois, which holds a crucial primary on Tuesday.
But the front-runner for the Republican nomination decided Friday to return to Illinois a day earlier than scheduled, a sign of the urgency Romney's campaign feels to win Illinois over rival Rick Santorum.
Aides to Romney said only that the former Massachusetts governor wanted to spend more time in Illinois, but a campaign that typically plans its schedule days in advance seemed to be scrambling on Friday to make Illinois a higher priority.
Romney is still in a commanding position in the race to determine who will face Democratic President Barack Obama in the Nov. 6 election.
He has a big lead in support from party delegates whose backing is needed to win the nomination, but his campaign is eager for a symbolic victory to counter the momentum Santorum picked up by winning in Mississippi and Alabama on Tuesday.
Romney's campaign is desperate for another signature win - like those it had Michigan, Ohio and Florida - to solidify his front-runner status and tamp down Santorum's hopes of capturing enough support from party conservatives to derail Romney.
"I get the sense that Illinois has turned into the new Michigan for the Romney campaign. They must stop Santorum there at all costs to continue their narrative that Romney cannot be overcome via delegate math," said Republican strategist Ron Christie.
"Given the time and resources available, I believe the Romney team has concluded that Illinois is the key victory they must obtain rather than Puerto Rico," Christie added.
Romney's campaign could have increasing confidence that he will win Puerto Rico because of remarks Santorum made this week which angered some Puerto Rican officials, saying that if Puerto Rico wants U.S. statehood, it would have to legally make English its official language.
Santorum incorrectly told an interviewer any U.S. territory that wants to join the United States must meet that requirement. The former Pennsylvania senator has since said he was misquoted.
Upon landing at a private airstrip in San Juan, Romney seized on his opponent's misstep, declaring he would assist Puerto Rico in pursuing statehood if that's what its citizens voted to do.
Romney noted that Puerto Rican Governor Luis Fortuno, who appeared with Santorum this week despite endorsing Romney, asked him his views on statehood before offering his endorsement.
"I pointed out the same thing I pointed out when I was running for office three years ago, which is that I respect the rights of Puerto Ricans to make their own decision with regards to statehood," Romney said.
"And if they choose by a majority plus one person to become a state, I will help lead the effort to provide statehood for the citizens of Puerto Rico would seek."
Puerto Ricans are not allowed to vote in November's election, but they do have a significant voice in the Republican nominating contest. Twenty-three delegates are at stake in Puerto Rico on Sunday; in the Illinois primary on Tuesday, 69 delegates are at stake.
Romney leads the delegate race with nearly 500 delegates, almost double Santorum's total. A Republican candidate needs 1,144 to clinch the party's nomination.
© 2014 Thomson/Reuters. All rights reserved.