Santorum looks to build on two big primary wins

An upbeat Rick Santorum barreled into Puerto Rico in pursuit of another victory in a Republican presidential race where suddenly no primary is too minor and no delegate is conceded. Mitt Romney put nearly $1 million into television advertising in Illinois, the next big-state showdown.

"If we keep winning races, eventually people are going to figure out that Governor Romney is not going to be the nominee," said Santorum, eager to build on Tuesday's unexpected victories in Alabama and Mississippi.

Republican presidential candidate, former Pennsylvania Senator Rick Santorum, speaks to an audience at a town hall meeting in San Juan, Puerto Rico, on Wednesday. [Dennis M. Rivera Pichardo / Associated Press]

Romney on Wednesday dismissed Santorum as a "lightweight" on the economy - by far the most important issue as Republicans jostle to challenge President Barack Obama in November.

Romney also rebutted suggestions that he can't appeal to core conservatives, after a wave of evangelical Christian voters led this week's voting and left him in third place in both states.

"You don't win a million more votes than anyone else in this race by just appealing to high-income Americans," the multimillionaire told Fox News. "Some who are very conservative may not be in my camp, but they will be when I become the nominee, when I face Barack Obama."

Romney remains far ahead in the overall race for the delegates crucial to winning the nomination at the Republican national convention in August. Incomplete returns showed him actually adding one or two to his advantage because of overnight caucus victories in Hawaii and American Samoa.

Romney's aides point out that he has more than half the delegates picked so far.

The former Massachusetts governor travels to Puerto Rico on Friday, after two days of fundraising in New York.

But in a reflection of the importance of next week's Illinois primary, aides announced Romney would make a previously unscheduled campaign stop in the Chicago area en route to Puerto Rico - where residents cannot even vote in the fall election.

This week's events summarize the most turbulent Republican presidential campaign in a generation.

Santorum is eager for a race in which he is the sole conservative challenger to Romney. But Newt Gingrich, despite losing twice in the South, a region he hoped to own in the race, shows no sign of abandoning his fading campaign.

Santorum's camp has outlined a strategy that relies on outmaneuvering Romney in caucus states where delegates have yet to be picked.

"Simply put, time is on our side," the Santorum campaign said in a memo this week. The campaign pledged a floor fight at the national convention, envisioning two or three rounds of balloting before a nominee is selected.

While the campaigns maneuvered for position, the race was on for the primaries in Puerto Rico on Sunday, Illinois on Tuesday and Louisiana on March 24.

Santorum hopes to add Louisiana to his list of Southern successes, and he held his Tuesday night victory rally there.

Romney's $1 million television campaign in Illinois came on top of $2.4 million that a super political action committee supporting him was spending on advertising. Polls show a competitive race in that state, with Romney leading.