(AP) WASHINGTON - Often seen as a cool, calculating concealer of emotions, Barack Obama says he choked up while practicing a campaign speech about Martin Luther King Jr. But the president-elect promises to "try to keep it together" when he is sworn in Tuesday as the first black commander in chief.

He also said that when his family read quotes from Abraham Lincoln during a recent visit to the Lincoln Memorial, his 10-year-old daughter said her dad’s precedent-making inaugural address had "better be good."

In a broadcast interview taped Friday, Obama talked in more personal terms than usual about the racial and emotional dimensions of his election.

"If you think about the journey this country has made, then it can’t help but stir your heart," he said. "Obviously it’s an extraordinary personal moment," he added, but it carries far-reaching social and political implications.

"You can think about what Washington, D.C., was like 50 years ago or 60 years ago," when the city was segregated, Obama said, "and the notion that I now will be standing there and sworn in as the 44th president, I think is something that hopefully our children take for granted. But our grandparents, I think, are still stunned by it, and it’s a remarkable moment."

When asked about the deep emotion that many blacks will feel at his swearing-in, Obama said, "Well, I’m going to try to keep it together." But at the Democratic convention in Denver last August, he said, "there was a moment at the end of my convention speech where I talk about Dr. King and what he accomplished. And the first time we practiced it, I had to stop. I started choking up, because, you know, when you start thinking about is not just your own personal journey. But you think about all the women who walked instead of riding the bus, out in Montgomery and Birmingham, and what a moment like this would mean to them."

Remarkably, he said, "some of them are still alive."

He was referring to boycotts of city buses in Alabama when blacks had to give up their seats to whites.

Obama also spoke of his visit last weekend to the Lincoln Memorial with his wife, Michelle, and their daughters Sasha, 7, and Malia, 10. He said Sasha noted of Lincoln’s second inaugural address, "Boy, that’s a long speech. Do you have to give one of those?"

Obama told her that his speech Tuesday might be even longer.

"At which point then Malia turns to me and says, ’First African-American president. Better be good,’" Obama said.

CNN released a transcript of the interview for "State of the Union" ahead of the show’s Sunday broadcast.