Ben Carson had just started a stump speech to his staff, the one about freedom, and political correctness and the nation being on a dangerous path when he stopped. He clasped his hands and pressed his forefingers into the bridge of his nose.

“I’m sorry,” he said in a whisper as his staff members sat silently. “I started thinking about my mother. I got some news today that she is dying.”

Just a few hours earlier, in his hotel room in his home town of Detroit, Carson had received a text from one of his cousins that just read: “Is this a good time to talk?”

“I knew she wouldn’t be calling me about just anything, knowing it was the day before the announcement,” he said in an interview with The Washington Post. He was less than 24 hours from announcing that he would seeking the Republican nomination for president, and he was about to find out that his mother, who has had Alzheimer’s disease since 2011, probably would die within days.

“I had been struggling with what to write,” said Carson, who had not yet written his announcement speech. “But after my initial cry, my mind became very clear and I knew immediately what I wanted to talk about.”

He would, like he has done so many times before on the pre-campaign trail, talk about one of the most important women in his life. After the speech, Carson will fly to Dallas, canceling his first big rally in Iowa as a candidate, to say his final farewell.

“There has to be a mourning process,” Carson said. “And then I’ll move on.”

Sonya Carson has featured prominently in Carson’s telling of his life story. For before there was the conservative icon running an insurgent campaign for president, before there was a world-famous neurosurgeon, or a biopic starring Cuba Gooding Jr., there was a screw-up kid with a temper. That kid needed a mom like Sonya to get him in shape.

Sonya had 24 siblings and was married at age 13. When she found out that her husband, Ben’s father, had a second family, they divorced. Unable to read, Sonya encouraged her kids to stop watching television and read two books per week.

“I grew up to who I became because I had my mother,” Carson said at the Detroit Music Hall, where he had come to watch a rehearsal of his announcement day festivities. “It would have been nice to have her today. She developed Alzheimer’s in 2011. Sometimes I think it’s not the worst thing. She’s very feisty. She would have been on the warpath for people who tell lies about me, she would have been ready to shoot them.”

Carson maintained his composure during the rehearsal, trying to balance two of the biggest things that had ever happened to him at the same time. He sat quietly and watched as the Selected of God Choir performed its version of Eminem’s “Lose Yourself,” and smiled his way through a walk-through of his stage directions. Staff members came up to wish him the best, to which he said that death is part of the cycle of life.

“We’re trying to make it so we can stop over in Iowa so we can say goodbye,” Carson told his wife after she had rehearsed her violin accompaniment to the National Anthem.

“Good good,” she said. Then she pivoted to a question about her violin playing. “Did it sound okay in the end?”

“Yeah, it sounded much better,” he said.

When asked whether she was excited, Candy Carson, Ben’s wife, said, “I’m just thinking about his mom. I didn’t hear about it until today, too.”

The Carsons went out for dinner, and the staff met in the hotel lobby.

“Dr. Carson never had a father,” Carson’s business manager and friend Armstrong Williams told the crowd. “Everything that he’s ever had and ever known was his mother. . . . He has to go and make peace with his mother, because if he doesn’t, nothing will be the same.”

The crowd joined hands and prayed and cried.

“Don’t forget, he’s human like all of us,” Williams said.