MICHEL MARTIN, HOST:

Finally today, I have been thinking about Ohio Senator Rob Portman. He is a Republican. He was on the shortlist for Republican vice presidential nominee in the last election. While he's not been outspoken on the subject of same-sex marriage, he has consistently opposed it - until now. Recently, Senator Portman announced that he has changed his mind. He says this is because his own son, Will, is gay. Senator Portman talked about this with CNN's Dana Bash.

SENATOR ROBERT PORTMAN: I've come to the conclusion that for me, personally, I think this is something that we should allow people to do, to get married and to have the joy and the stability of marriage that I've had for over 26 years. I want all of my kids to have it, including our son, who is gay.

MARTIN: Now, you probably don't need me to tell you that you rarely go wrong by questioning a politician's motives. An example is the ever popular I'm resigning to spend more time with my family. Which of course generally means I know I'm not going to win anyway and oh, by the way, I'm having an affair with a staff member.

Still, let's take Senator Portman at his word - that his opinion about gays and lesbians and who they are and what they should be able to do was formed by a certain worldview. And it made sense to him until he had to reconcile that worldview with another truth, the truth of his son's life and the truth that he is the same boy Portman has loved and respected his whole life and for whom he wants the best.

And Senator Portman is not alone in this. A Pew Research study just released this week found that more than a quarter of the people who say they now support same-sex marriage say they had a change of heart on the matter. Actually, the question says they changed their minds, which may be different. But I think the heart was involved because a third of those people say the reason they changed their opinion was that they know someone who's gay.

Now, if that makes sense to you, then maybe somebody can explain why it didn't make sense to some people for President Obama to openly grieve over the death of a Florida boy named Trayvon Martin. He was shot to death after he bought snacks at a convenience store because a man he didn't know found him threatening. Obama was criticized because he pointed out that Trayvon's death hit him particularly hard, in part because Trayvon could've been his son. So in essence, he was criticized for governing while black, allowing his life experience to inform how he saw a particular issue.

Can I just tell you? Life experience really does matter. I read once that former President Lyndon Johnson was influenced in matters of civil rights at least as much by one of his housekeepers and the indignity she had to suffer on her trip South as he was by the entreaties of the civil rights leadership.

But could it be that this is one reason our progress now so often stalls on difficult issues like law enforcement, crime and race? Could it be that conservative whites like Senator Portman can't envision a scenario where their own children could lose their lives on a run to the store for snacks?

And on the other side of it, could it be that that's one reason Mr. Obama sometimes stumbles? Because he so thoroughly represents and lives the America we are fast becoming - browner, younger, mixed, and multinational - that he sometimes forgets how frightening this new world is to the people who were comfortable in the old one.

So yes, life experience, it matters. It matters that a leader loves and cares for his own children, but that to me is a necessary condition, not a sufficient one. The test of leadership is not how much someone cares about his own kids, but how much he or she can care for and dream dreams for all those children he's never met - yours and mine included. Transcript provided by NPR, Copyright NPR.