If Mitt Romney proved anything last weekend with his victories in Guam, the Northern Mariana Islands and the Virgin Islands, it is that the Republican presidential nomination this year might not be won by high-profile triumphs in states such as Iowa and South Carolina, but rather by diligently and methodically amassing delegates in far-off contests.

That makes Sunday's primary in Puerto Rico more important than you might think. Twenty-three delegates will be up for grabs when voters in the island commonwealth head to the polls this weekend, nearly as many as there were in more publicized battles in Michigan - 30 - and Arizona - 29.

It should come as no surprise, then, that Romney and rival Rick Santorum are set to campaign there only days before the primary. Newt Gingrich might soon follow.

"Puerto Rico is important for candidates because of the number of delegates and the projection in Florida, and to a lesser extent, other states with growing numbers of people hailing from Puerto Rico," said Javier Ortiz, a Republican political strategist.

Romney, with his strong campaign organization - as evidenced by his wins last weekend - and his resounding victory in Florida's January primary, appears to be the favorite. In a primary fight that has morphed into a question of math versus momentum - Romney's huge delegate lead versus Santorum's various winning streaks - the contest in Puerto Rico has the potential to pad the lead of the former Massachusetts governor.

Of the commonwealth's 23 delegates on offer, 20 will go to the candidate who wins more than 50 percent of Sunday's vote. That leaves three super delegates left and two have already endorsed Romney, including Puerto Rico Gov. Luis Fortuno, with the third one backing Gingrich. If no candidate wins a majority of the vote, the delegates will be allocated proportionally.

"All politics is local," Ortiz noted. "Romney has Governor Fortuno's endorsement and the impressive list of delegate candidates he lined up."

Adolfo Krans, a political analyst who hosts a daily radio talk show on the island, predicted that the turnout in Sunday's primary will be high - some projections hover around 400,000, which would be more than the first two primary states to vote - Iowa and New Hampshire - combined - and that Romney holds the upper hand.

"For the first time Republicans will be able to say that we are having a substantial amount of participants going to vote, sending a message that has been lost for many years because for some reason Puerto Rico has always been identified as a place in favor of the Democrats," Krans said in an interview.

"It's going to be fun and it's going to be very positive for the Republican party to send a message that Puerto Ricans are not necessarily in favor of the Democratic party in the United States," he added. "For me, that's the most important thing in the event and, of course, knowing that the governor is an active Republican who has favored Romney means that it is easy to say that Romney will come out ahead."

Jose Luis Fernandez, the host of "Mesa Presidencial," a show on Univision Radio WKAQ 580AM in Puerto Rico, is not so sure. He believes that Santorum has the potential to exceed expectations on the island and ensure a split of the 23 delegates.

"Even though Governor Fortuño endorsed Romney, and many believe that it would be easy for him to get the 23 delegates, it may not necessarily be the case," Fernandez said. "I have heard of Democrats, many within the Popular Democratic Party [commonwealth advocates] in Puerto Rico mobilizing their people to vote for Santorum or against Romney. Remember what happened in Michigan, where over 100,000 Democrats voted for Santorum. If commonwealth supporters actively encourage their people to vote for Santorum, this could present a difficult scenario for Romney.

"There is an opportunity for Santorum in Puerto Rico if he is successful in reaching out to evangelicals and if Democrats vote for him in the primary," Fernandez continued. "Many people are also unaware that they do not have to be affiliated with the Republican Party in order to vote; technically everyone can vote. These factors could be game-changers in Puerto Rico. It may not be that easy for Romney and he may have to share delegates again."

One potential stumbling block for Romney is a recent campaign ad that alienated some Latinos. In the ad the Romney campaign criticized Santorum, as a senator in 1998, for voting for Sonia Sotomayor to the Second Circuit Court of Appeals, a vote that the ad said put her on the fast track to becoming a Supreme Court justice years later. But the spot soon drew criticism from Latino groups, such as the National Institute for Latino Policy for one,- for attacking Sotomayor, whom the group called "an icon for the Latino community."

"This has not been well-received by many Puerto Ricans and the Hispanic community," Fernandez said.

Ortiz said, "Romney may lose some steam because of his open negative mentions of Justice Sotomayor."

That may explain, in part, why both Romney and Santorum are visiting the commonwealth this week, the former to consolidate his support, the latter to try to spring an upset. The campaign stops are far from unprecedented - Barack Obama and Hillary Clinton went there four years ago - but they come this year at a pivotal time in the GOP primary, only days after Alabama and Mississippi vote and days before Illinois takes its turn. Santorum will even hold a press conference Wednesday with Fortuno, whom he praised in January as "a good friend of mine."

"We have known each other for many years," Santorum said. "We actually used to go to church together."

But when Fortuno endorsed Romney, the governor praised the GOP front-runner as "the one candidate who has the record, leadership, experience and pro-growth plan to continue the course of private-sector job creation we've begun in Puerto Rico and provide economic stability for generations."

In Puerto Rico, economic problems are a major issue, and that is one of Romney's strong suits. The island's population has been decimated in the past decade by residents leaving for the mainland, in large part because of better economic prospects there. Around 420,000 Puerto Ricans now live in Florida, for instance, a group heavily concentrated around the politically crucial Interstate 4 corridor in the central part of the state.

"The census showed the population was lower in 2010 than it was in 2000 and one of the elements is Puerto Ricans relocating to places like Florida and New York," Krans, the radio talk-show host, said. "They go there for financial reasons. The economy is not good here. I'm a business person and it's very similar to what you see in the United States.

"Nobody else can hit that credit card more than a Puerto Rican, so all the big chains fight to come here. We don't have a lot of discipline in spending our dollars. We are now facing the same economic situation as people are facing stateside. We're turning around, but not as fast as we should, not as fast as in the States."

Another issue on the island is the looming question of statehood. Puerto Rico will have a referendum later this year on whether to become a state, something some Puerto Ricans favor and others oppose, whether it be in favor of remaining a commonwealth or becoming independent. At an event in Miami in January, Romney said he expects "the people of Puerto Rico will decide that they want to become a state and I can tell you that I will work with [Fortuno] to make sure that if that vote comes out in favor of statehood, that we will go through the process in Washington to provide statehood to Puerto Rico."

It all sets the stage for an intriguing primary contest come this weekend, giving Romney a chance to pad his lead, but his rivals a chance to spring a surprise. Whoever comes out on top will likely try to make the argument that it is a testament to his strength among Latinos, the nation's fastest-growing voting bloc.

"The outcome of the primary will send a strong message to the nearly five million strong Puerto Rican community in the mainland and encourage them to be even more politically involved in the 2012 general election, particularly in key swing states such as Florida, with a very significant Puerto Rican community," Fernandez  of "Mesa Presidencial" noted.

Obama enjoyed a 63 percent approval rate among registered Latino voters nationwide, compared to only 28 percent for Romney, according to a Latino Decisions poll conducted in January for ABC News and Univision.

Whether Romney or any of his fellow GOP hopefuls can turn that around and win Latino support in this fall's general election remains to be seen, but they all hope that success Sunday in Puerto Rico's primary will be the first step in that process.

Matthew Jaffe is covering the 2012 campaign for ABC News and Univision.