The following is a rush transcript of the January 15, 2012 edition of "Fox News Sunday With Chris Wallace." This copy may not be in its final form and may be updated.

CHRIS WALLACE, HOST: I'm Chris Wallace.

Conservative Christian leaderships endorse Rick Santorum as they try to unite social conservatives behind one man.

Can anyone stop Mitt Romney? We'll talk to a candidate who tied for first in Iowa but lost steam in New Hampshire. Rick Santorum and his strategy for a come back as we continue our 2012 one-on-one series of interviews.

Then, some of Romney's rifles slam his business as vulture capitalism. We'll have a debate over private equity between Chris Chocola, head of the Club for Growth, and Rick Tyler, part of the pro- Gingrich super PAC behind the ads.

Also, will a controversial video derail U.S. peace talks with the Taliban? And who is behind the covert operation in Iran who killed a nuclear scientist? We'll ask our Sunday panel how both incidents will affect U.S. foreign policy.

And from the first in the nation primary to the no holds barred fight in South Carolina, we go on the trail.

All right now on "Fox News Sunday."

And hello again from Fox News in Washington. Well, there has been a big development in the Republican race for president. For months now, social conservatives have split their votes among the several candidates, leaving a clear path for Mitt Romney to be the front runner. But in a summit of Christian leaders in Texas yesterday, a super majority voted to back Rick Santorum. This just six days before voters in South Carolina go to the polls.

Joining us now from Myrtle Beach is the former senator from Pennsylvania.

And welcome back to "Fox News Sunday."

RICK SANTORUM (R), PRESIDENTIAL CANDIDATE: Thank you very much, Chris. Good to be with you.

WALLACE: Senator, how big of a deal is this? And especially, what's the practical effect on your campaign with just, as we say, six days before the primary?

SANTORUM: Well, it's a great -- it's a very big deal. The bottom line is that you have folks there representing a lot of different camps. A lot of people who came there to win the day for the candidate, and it was a very divided group at the beginning.

But as they work through it, they came to a consensus, an overwhelming consensus, like 75 percent of the people there decided to support me. And I think they did so because they know that I'm the consistent conservative. I'm someone who's willing to stand up for all of the issues, not just the moral and cultural issues, but economic issue and the moral crisis of this debt and this explosion of government and willing to stand up against radical jihadism and the things that are important to conservatives across in this country and they saw me as the one best chance of winning.

I beat Gingrich and Perry in Iowa. I beat them again in New Hampshire, and we're doing well here.

So, we feel very, very good that with their support, we're going to get a network of grassroots leaders here, lining up behind us and giving us that surge that we need coming down to this last week.

WALLACE: Have they made any promises, the ones who endorsed you, of giving you money, of going out publicly in supporting you?

SANTORUM: I haven't really talked to any of them. I talked to one person, to be honest with you, since that meeting. And what I was told that individual members are going to go out and do things with, you know, either endorsements or contacting people here in the state and across the states to support us and to help our cause. And we certainly accept all endorsements and help and money and grassroots activity -- anything they're willing to do to help, we'll be happy to take it.

WALLACE: But the fact is, the practical fact is, you have been splitting the vote of social conservatives with Gingrich and with Perry, should they drop out of the race so that the votes of those social conservatives can be united in supporting a candidate who supports their views?

SANTORUM: I'm not going to tell anybody to get in or out of the race. I think that's their decision to make. We're going to run the race as hard as we can and South Carolina is going to have big impact on this race, but it's not going to be the final issue. There are a lot of the races and a lot of states to come. We need to get this eventually down to a conservative alternative to Mitt Romney. And those -- when we finally get matched up, and we believe it will be us. When we get matched up, if you look at the polls done in other states down the road, we match up very well and ahead of Governor Romney almost every one of those state polls.

So, feel like once this field narrows, when we get it down to a two-person race, we have an excellent opportunity to win this race.

WALLACE: But, and I take your point you're not asking them to drop out. As long as they stay in the race, however, Perry and Gingrich, doesn't it have the practical effect of helping Romney and doesn't it diminish the effectiveness of social conservatives in trying to help pick the nominee?

SANTORUM: Well, I don't think it's just social conservatives. It's all conservatives. I think a lot of conservatives have concern about Governor Romney's record on the economy and Romneycare as a real scarlet letter here that we can't have a nominee that takes away the most important issue of this election which is an explosion of federal government and robbing the people's freedom on the federal level with Obamacare and Romneycare, which was the predecessor to Obamacare, just disqualifies him and his ability to go out and aggressively go after this top down approach to health care.

So, this is not just social conservatives. I'm hearing from conservatives across the board, economic, foreign policy. They're looking for someone with a strong consistent track record. And I'm hopeful -- again, you know, will it help? Yes. It would be helpful if everybody drop out and I would win. But, you know, the idea is, we're going to go through this process, people have the right to go out and make the case to the voters and then we'll see what happens.

WALLACE: Given that Newt Gingrich is beating you right now in the polls in South Carolina, why should his supporters back you? Why are you a truer conservative than Newt Gingrich?

SANTORUM: Well, I'll just look the -- at our leadership. When I was in the Republican leadership in United States, conservative organizations from national security to economic to social conservatives came to me to make sure that the conservative agenda was pushed in our leadership and made sure that those voters came to the floor of the United States Senate whether it was the NRA or the National Restaurant Association, or the National Rifle Association, those folks came and they understood we were the conservative voice of the leadership. We were the ones who were out there taking it to the streets, if you will.

And if you look at Congressman Gingrich when he was speaker, three in to his speakership, there was a conservative revolution because they were concerned that he was not promoting those ideas.

So, when you look at someone in their leadership ability and what they do when inside of the room when nobody else is watching, we were the conservatives that stood up and fought. And Newt was not. And that's what we're looking at in the present. We're looking for someone who can lead and someone who's not afraid to take on those issues and put the real, tough conservative issues on the backburner.

WALLACE: Let's talk about your record as a conservative, senator. When you were in the Senate, you voted against the national right to work law which would have allowed people to get jobs without having to join a union. For years, you repeatedly supported the Davis-Bacon Act which requires government contractors to pay the prevailing wage.

In both of those issues, you sided with big labor, sir.

SANTORUM: Yes. I think if you look back in my track record, I think I had about a 9 percent big labor voting record. You picked out the two.

And you need to remember, I was from the state of Pennsylvania. State of Pennsylvania does not have a right to work law. The state legislature and our governor for a long time had rules in place that were inconsistent with right to work.

And I wasn't, as United States senator, representing the states of Pennsylvania going to go down and by federal vote change the law on the state. I believe the state has the right. If they want a union dues requirement, that the state should be able to do that.

As a president, I have a very different point of view. I have already signed a letter and sent it to the national right to work that I would sign a national right to work bill because now, I'm no longer representing that state.

And by the way, the same thing with respect to Davis-Bacon. My feeling was, again, representing that state, which has a large segment of contractors that work under those provisions that I would protect that right.

Again, as a president, I would have a different view. But I did represent a constituency and one of the things I think is important is to listen and respect the rights of my state.

WALLACE: But how is that different than Mitt Romney who took some positions when he was a governor of Massachusetts and changed some of his positions since then?

SANTORUM: Well, if I was governor of Pennsylvania, I would have worked to change those laws.

WALLACE: But you were senator of Pennsylvania.