(Image Credit: AP)

SHREVEPORT, La. - On the eve of the Louisiana primary, Rick Santorum reserved the majority of his attacks for Mitt Romney, arguing that Romney calculates running as a conservative while Santorum is a true conservative.

"When he was asked the question about this Etch A Sketch comment, he said oh no no, I'm planning on running as a conservative. Ladies and gentleman, I am a conservative, I don't have to plan on running on anything," Santorum told the crowd at a rally at a downtown Shreveport hotel.

Santorum, who said the election is down to "two on the Republican side and President Obama," ripped into Romney for switching his positions on English requirements in Puerto Rico for statehood, his support of carbon caps, and allegedly advocating for higher gas prices.

"Governor Romney when he was governor of Massachusetts said that we have to get used to high gas prices and no one wants to go out and produce more gasoline that this is not good for the environment. That's what Governor Romney believed, now he's running again as a conservative. And now he's says I'm not for cap and trade anymore even though he put in carbon caps when he was governor of Massachusetts, advocated for higher gas prices. Now he's for more drilling. Now he's for all the things that all those voting in republican primaries want to hear. How many of you believe that's what he'll stay with?" Santorum asked as members of the crowd yelled "No!"

Santorum, who is leading Romney in recent polls in the state, linked Romney to Obama based on their health care plans and contended that electing Romney would limit the Republicans' ability to point out the president's vulnerability on this issue.

"It the biggest Achilles heel of this president. It the biggest Achilles heel of this president and we take the spear out of the hands of the Republican nominee by by not being able to pinpoint where that problem is  and to take President Obama out of the White House," said Santorum.

Santorum criticized Obama's announcement Thursday in Oklahoma where he said the administration would "cut through the red tape" to put the construction of the southern segment of the XL pipeline on a fast track.

"The audacity of the president of the United States going to Oklahoma and taking credit for something he had absolutely nothing to do with, which is the building of the pipeline here in the south. It's laughable. The one place he could actually do something, what did he say? No. He said no about bringing from Canada, getting that oil shall from North Dakota, bringing it down here to refineries here in the South. He said no," said Santorum.

Santorum, who is holding three events in Louisiana Friday ahead of Saturday's primary, told the crowd of over 100 people that he's immensely enjoyed his time in Louisiana but admitted the Southern cuisine has been "working on my waistline," which he acknowledged as a problem area, especially after the photos emerged of him shirtless in Puerto Rico two weeks ago.

As he greeted voters along the ropeline, one reporter asked Santorum his opinion on the Denver Bronco's trade of Tim Tebow, to which he responded: "I'm a big Tebow fan so whatever the best place for him to play, I'm for it."