Scott Walker on Donald Trump, Family Politics

Transcript for Scott Walker on Donald Trump, Family Politics

Finally tonight, republican presidential candidate Scott walker going up against pretty famous family names. Among his fellow contenders, the trumps, the bushs. Tonight he is letting ABC news anchor David Muir in for an unfiltered look at his own family. There is enoughing off-limits in this candid interview. Reporter: Scott walker is officially running for president and she is aware how many announced before him. You are the 15th republican now to fight for this nomination, what do the American voters not know about you that helps seal the deal? If the republicans will take on a name from the past like Hillary Clinton they need a name for the future. Jeb is a good guy. There are a lot of people talking about Donald Trump right now, he is leading in some polls. Jeb bush said he believes what trump has said about Mexicans is really meant to enflame and inc incite. Do you agree? Donald Trump and others can speak for themselves. Eventually you could be on the debate stage with trump. If he says what he said what will you say? I respectfully disagree with him. I have a policy when it comes to immigration. Secure the border. Enforce the law. I don"t believe in amnesty. Reporter: We drive to Wisconsin, and one of his first jobs at this McDonald "S. The grill where he once stood still there. The second drive through is new. Just checking out the old stomps here. Reporter: For the first time his family sits down with us at the governor"s mansion in Madison. With your dad running for president, with your husband running for president, I"m curious how does the family feel? We have been telling our dad we think he should. I think we are ready for it. You can never be ready for this, I guess, we have had quite a few campaigns in the last four years. I think we are ready. Reporter: When he first met his wife she was from a democratic family. Reporter: You got married on Ronald Reagan"s birthday? We did. I don"t know if I knew that at the time. Reporter: He counts on her for guidance. They don"t always agree. Nor do the boys. After the supreme court ruling on same-s*x marriage. They were on one side, dad on the other. Reporter: You called it a great mistake. Not everybody agreed. Her cousin married her partner. One of the governor"s son a witness at the ceremony. Roichl W Reporter: When your husband the governor says it was a great mistake. What do you say? I was more concerned that I got calls from both the boys upset about what Scott had said. And so, my advice to them was, don"t come to me. Go to him. He said it. Reporter: You haven"t changed your stance? No, no. We love them. And for us, you know, love is going to be the focus of everything we do with our family. Reporter: They talk a lot about family. His mother and father a Baptist preacher. He might share his idol Ronald Reagan with someone else. One of your college profess professors said you wore three piece suits instead of jeans like teaching Alex P. Keating. I got to attend all right evening meetings. Alex P. Keating not a bad thing. Funny. Are you ready for the race? I"m excited. I"m David Muir for "Nightline" in Madison.

This transcript has been automatically generated and may not be 100% accurate.

Source: http://abcnews.go.com/Nightline/video/scott-walker-donald-trump-family-politics-32431996