He is running for the Senate as an immigrant who made good, reaching out to Ohio voters with a stirring, only-in-America bootstraps story: arriving as a child from Colombia, taking a risk on a struggling business, and then turning it into a smashing success and himself into a millionaire 100 times over.

Running under the banner of Donald J. Trump’s populist political movement, Bernie Moreno, the Republican challenging Senator Sherrod Brown, humbly calls himself a “car guy from Cleveland” and recounts the modest circumstances of his childhood, when his immigrant family started over from scratch in the United States.

“We came here with absolutely nothing — we came here legally — but we came here, nine of us in a two-bedroom apartment,” Mr. Moreno said in 2023, in what became his signature pitch. His father “had to leave everything behind,” he has said, remembering what he called his family’s “lower-middle-class status.”

But there is much more that Mr. Moreno does not say about his background, his upbringing and his very powerful present-day ties in the country where he was born.

Mr. Moreno was born into a rich and politically connected family in Bogotá, a city that it never completely left behind, where some members continue to enjoy great wealth and status.