(GOOGLE) — WASHINGTON (AP) — Mitt Romney took a commanding lead Sunday in early voting returns as Puerto Rico weighed in on the fight for the Republican presidential nomination. He and his chief rival, Rick Santorum, however, were nowhere to be found on the Caribbean island, campaigning instead in Illinois and Louisiana ahead of primaries in those states this week.

The race was all but certain to continue, regardless of the outcome of the trio of contests.

As the day began, Santorum claimed he was in contest for the long haul because Romney is a weak front-runner even though he comfortably leads in the fight for delegates to the nominating convention.

“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.”

Note: Read our discussion guidelines before commenting.