SAN JUAN, Puerto Rico - Mitt Romney scored an overwhelming win Sunday in Puerto Rico's Republican presidential primary, trouncing chief rival Rick Santorum on the Caribbean island even as the two rivals looked ahead to more competitive contests this week in Illinois and Louisiana.
The victory in the U.S. territory was so convincing that Romney, the GOP front-runner, won all 20 delegates to the national convention at stake because he prevailed with more than 50 percent of the vote. That padded his comfortable lead over Santorum in the race to amass the 1,144 delegates needed to clinch the nomination.
Nevertheless, the GOP nomination fight is unlikely to end anytime soon, with Santorum refusing to step aside even though Romney is pulling further ahead in the delegate hunt.
As the day began, Santorum claimed he was in contest for the long haul because Romney is a weak front-runner.
"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. "That tells you that there's a real flaw there."
Yet, Santorum sidestepped when asked if he would fight Romney on the convention floor if he failed before August to stop the former Massachusetts governor from getting the required number of delegates.
Romney, in turn, expressed confidence that he'd prevail.
"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."
Both campaigned in Puerto Rico last week - in a campaign focused on statehood for the U.S. territory - but Romney cut short his trip so he could head to Illinois and Santorum spent Sunday in Louisiana. Illinois, a more moderate Midwestern state, votes Tuesday and is seen as more friendly territory for Romney, while Santorum is the favorite in the more conservative Southern state of Louisiana, which votes Saturday.
After the Puerto Rico victory, Romney had 521 delegates in his camp and Santorum had 253, according to the Associated Press' tally. Former House Speaker Newt Gingrich trailed with 136 delegates and Texas Rep. Ron Paul had 50.
Enrique Melendez, the Republican representative on the Puerto Rican State Electoral Commission, said Romney "won the Puerto Rican primary by a huge margin and we are granting him the 20 delegates."
At this rate, Romney is on pace to capture the nomination in June unless Santorum or Gingrich is able to win decisively in the coming contests.