TUCSON, Ariz. - Campaigning at a Tea Party rally today, Rick Santorum zeroed in on immigration in this southern Arizona city as he promised to "secure the southern border" and make  illegal immigration  a focal point of his presidency.

"You have my pledge that we will secure this border. We will deal with the issue of the drug violence and the cartels, we will work with the Mexican government to make sure that we  … have relationships there that can help strengthen their economy, deal with the national security threats to our country at the border and secure the border so that people in Arizona can live in peace and prosperity just like every other state in the county," said Santorum.

Unlike his campaign stops Tuesday in Phoenix, where he mentioned immigration only once at one event, Santorum focused on the issue here in Tucson, which is 70 miles from the Mexican border, eliciting cheers from the crowd as he told the story of how his grandfather left his family in Italy to come to the United States legally.

"I share that, that concern that many people have. Well, what are we going to do with all these people in America.," Santorum said to a crowd of about 200 at a Shriner's Hall. "Well, I look at it from the standpoint of my grandfather. My grandfather came to this country, he came in 1925. He came by  himself. He left his family behind, his young children, his wife, he left them after having served in World War I.  But came to America, sacrificed five years of his life … until he was able to refill the requirements and bring the rest of the family over.  "

Santorum said securing the border wasn't "hostile, this is just who we are."

There was increased security at the Tucson rally with bag checks and organizers telling an overflow crowd of about 50 people that the candidate would not be shaking hands outside due to security reasons. At the end of the rally, Santorum urged the candidates who spoke before him to "take this district back," but he did not mention former Democratic Rep. Gabrielle Giffords, who was shot in Tucson  last year.

Neither did he  mention the foreclosure crisis rocking this state, and he kept most of his hits on President Obama rather than his rivals, telling an enthusiastic and responsive audience who repeatedly shouted out disparaging comments about Obama, "We see a president who is systematically trying to crush the traditional Judeo-Christian principles in this country."

Santorum again defended the controversial Satan comments that popped up on the campaign trail Tuesday when audio was released of the former Pennsylvania senator saying Satan was attacking U.S. government and religious  institutions.   He said Obama was "making the world a much more dangerous place," and there were "forces of evil" at work in this country and around the world.

"You hear a lot of talk from me, as I mentioned this earlier, about the threats that we have around this world, and we do have serious threats that this president is uniformly making worse," Santorum said. "He's making the world a much more dangerous place as he continues to pull America back and allow those who seek to do harm to freedom, those who seek to oppress, yes, evil forces around the world. As Ronald Reagan was courageous enough to go out and speak about the forces of evil, not just around the world by the way but in this country, go read the speech. He went out and identified clearly why, because America stands for something, we stand for goodness we stand for freedom we stand for the dignity of every human person, that is who we are, that is why we're that shining city on the hill that the rest of the world looks to. … And yet our president refuses to call evil evil, refuses to even name it, refuses to confront it, tries to appease and cajole it in an effort to reduce America's commitments around the world."

He hardly spoke about his opponents today, but did say the country can't afford "pyrrhic victories."

"We need a victory that is actually gonna have consequence. We've had too many elections where too many politicians have promised what you wanted to hear based on what was popular at the moment, but what we need are candidates that you can trust, who are going to do what is necessary and what you believe needs to be done to turn this country back around," Santorum said in a seemingly veiled hit at Mitt Romney, who still leads Santorum in this state.

Santorum called his rivals "Johnny-come-latelys to the conservative cause" and urged the audience to vote for him on Tuesday.

"That's the decision you have to make here in Arizona," Santorum said. "Who do you trust? Who's authentic? Who's believable? Is it the guy reading from the teleprompter or the guy out here on a high-wire line telling you what's in his heart, and what's in his gut?"

"Getting to that peace and prosperity, we need to do two things to turn this country around economically," Santorum said. "First, we have to get the government off the backs of the American people and American businesses. I've put forward a plan that does both, grow this economy by changing the tax code. I just saw today that Gov. Romney announced that he was going to be lowering the tax rates to well, the tax rate I proposed. Welcome to the party, governor. Great to have you along"