Carson’s positions on economic issues, particularly combating poverty, were forged in his extraordinary rise from what is now a riverfront slum in the shadow of a long bridge to Canada. But those positions have created a tension in his run for president.

Carson holds up his life story as proof that anyone with enough faith and drive can climb the economic ladder — if they can avoid dependence on welfare. Critics say the decline of his old neighborhood underscores just how rare it is for someone born into Carson’s circumstances to do that without government help.

On his way up the ladder, Carson benefited from several government-assistance programs for the poor. In his autobiography “ Gifted Hands ,” Carson also praised the help he received from public school teachers, a federal jobs program, community mentors, government-supplied eyeglasses and, crucially, food stamps, without which his family “couldn’t have made it,” he wrote.

But he also wrote that his mother shunned dependency, citing her high expectations and his Christian faith for lifting him up. He says that throughout his life he was struck by poor people he met — first as a child, and later working in a hospital — whom he regarded as reliant on government checks.

“By the time I was a young attending neurosurgeon,” he recalled in an interview, “I was really struck by the number of indigent people I saw coming in who were on public assistance and who were not working. They were able-bodied people, and they were not working. I thought, ‘This is out of whack.’ ”

He added: “I don’t want to get rid of any safety net programs. I want to create an environment where they won’t be needed.”