Despite having a terminally ill child at home and performing dismally in the polls, GOP contender Rick Santorum, one of the field’s most conservative candidates, says he’ll remain in the race to send voters a message about the sanctity of life.

Santorum told ABC’s Christiane Amanpour that part of being a good father to his 3-year-old daughter Isabella, diagnosed with the genetic disorder Trisomy 18, is staying on the trail.

“I don’t worry about the polls, I worry about what I’m trying to do to be the best father and husband I can be,” Santorum, a former Pennsylvania senator,  said Sunday. “And obviously a big part of that is making sure that we have a country that respects her life and a country that is free and safe and prosperous for all of my children.”

“And I just felt like, given this is really I believe the most critical election in the history of the country, that I had to step up and make sacrifices, like everybody does, to make our country a better country,” he said.

Santorum, has seven children. Isabella, whom the family calls Bella or “Boo,” is the youngest. Half of all children diagnosed with Trisomy 18 carried to term die at birth, only about 1 percent live to be 10 years old, and fewer older than that.

“She’s an absolute joy,” Santorum said of the girl. “She’s really the center of our lives. And we feel so blessed to have her.”

Santorum has talked about his daughter before, fighting back tears at presidential forum last month in Iowa.

Santorum said he was the candidate who most reflected the importance the Republican Party has traditionally put on social issues and slammed front runner former Speaker Newt Gingrich for lacking “character.”

He also compared himself to Gingrich in their personal lives. Gingrich has been twice divorced and is on his third marriage.

“I think character is definitely an issue. You know, I think they have to make a decision based upon the person’s entire record. And certainly character counts,” Santorum said.

“I have been married 21 years. I have seven children, that’s a factor that people are going to look at and should look at when it comes to the person you’re going to have to lead the country,” he said.