Daniel D'Aniello (Astrid Riecken for The Washington Post)

Daniel A. D'Aniello, the co-founder and chairman of the Washington-basedprivate-equity giant Carlyle Group, is contributing $20 million to the right-leaning American Enterprise Institute.

The contribution by D'Aniello — set to be announced Tuesday — marks a new foray into policy advocacy by the top Carlyle executive, who has maintained a much lower profile than co-founder David Rubenstein. It also represents the marriage of one of Washington's business titans to one of its top think tanks.

AEI will name its new building after D'Aniello before moving in late next year. The building, at 1785 Massachusetts Ave. NW, formerly owned by Andrew Mellon and purchased from the National Trust for Historic Preservation, is in a neighborhood that houses a number of think tanks, including the Brookings Institution.

In a recent interview at Carlyle's offices, D'Aniello said that he decided to make the contribution because AEI's philosophy mirrors his own - a way of thinking nurtured in the 1940s and '50s in the coal-mining town of Butler, Pa.

"It's all about freedom, opportunity and enterprise," D'Aniello, 67, said. "Those are the watch words of AEI, so if I would think about my life, I would think about it in just that way."

AEI is at a key moment in its history. The organization has become an increasingly relevant source of ideas and policy proposals for Republicans as the party seeks to move its focus away from debt and spending and toward more politically popular policies that directly address the nation's top challenges, such as poverty and mobility. AEI has championed ideas such as tax credits for the poor that encourage work and vouchers that allow children to attend charter and private schools.

"With respect to the philosophical statements of AEI, the most important is driving a full understanding of what earned success is and what it can mean to your own happiness and success," D'Aniello said. "It's very disincentivizing to have others take care of your needs."

The contribution comes after years of discussions between D'Aniello, who is vice chairman of AEI's board, and Arthur Brooks, the organization's president.

The two first met at a board meeting of Syracuse University. D'Aniello attended the school, studying business and transportation logistics, and later served on its board. Brooks was a professor at the university before coming to Washington to lead AEI.

As two conservatives active in an academic institution, "we sniffed each other out after about five minutes," Brooks said.

Brooks said that the expansion will allow AEI to continue to grow rapidly — after expanding from 140 staffers in 2009 to 206 today. AEI will build radio and television studios, classrooms and other meeting spaces in an effort to expand its influence.

D'Aniello said that AEI's approach meshes well with his life experience. With his father out of the picture, D'Aniello went to work at a fruit market at just 9 years old. He was raised by his mother and grandmother.

"People ask how could I be so conservative," he said. "Well, I was born to people raised in 1889."

A high school gymnast, he planned to go to the Naval Academy, but a heart murmur got in the way. Instead, he attended Syracuse on a scholarship. After college, he served three years in the Navy doing logistics before going to Harvard Business School.

From there, he worked his way up through TWA, PepsiCo and Marriott before founding Carlyle in 1987 with Rubenstein and William Conway Jr. Carlyle has since become one of the biggest private-equity firms in the world. Forbes estimates  D'Aniello's net worth at $2.6 billion.

But it was long before he amassed his wealth that he developed his economic philosophy, he said, which is that people sometimes need help to get ahead, but they also need the freedom to pursue their ambitions without government getting in the way.

"Entrepreneurship requires flexibility and an open society, and there will always be people who succeed and people who follow," he said. "For those who lead, they have an obligation to create a better life for the people around them."

D'Aniello has concentrated much of his philanthropy on Syracuse, where he has backed internship programs, as well as an initiative to help veterans re-enter the workforce. He's also provided support for poor families in the Washington area.

"One of the biggest problems we have in the United States is really [that] the family is so diluted in many sectors of the economy that there's no support system at home," he said. "What that means is obviously education and instilling in young people the belief that they can have a better life."

D'Aniello said that he has succeeded in business because mentors were willing to bet on him.

"I was fortunate that someone was willing to invest in me, and that wasn't lost on me," he said. "I want other people to feel that way."