Phil Kent sits in the spring sunshine on the patio of a restaurant in the city’s upscale Buckhead district. Over the course of an April afternoon, Mr. Kent will discuss various projects with two newspaper reporters and a talk-radio producer who visit his table, and will field cell-phone calls from friends, business associates and clients of his Atlanta public-relations firm.

    "Holding court" is how Mr. Kent describes such occasions, combining his skills as a press-savvy wheeler-dealer with old-fashioned Southern hospitality.

    "In Atlanta, there’s a lot of business that’s conducted over breakfast, over long lunches and during happy hour," says Mr. Kent, a veteran newspaperman and commentator. "One of my hobbies is going to cocktail parties."

    Now, however, Mr. Kent is working on a more serious project: exposing the influence of nonprofit foundations in American society and politics.

    His new book, "Foundations of Betrayal: How the Liberal Super-Rich Undermine America," examines the history and activities of these institutions that, according to one estimate, control $500 billion in combined assets.

    "There have been a lot of books written on politicians and media and their impact on America," Mr. Kent says, "but there has been virtually nothing writing on America’s private, tax-exempt foundations."

    The major foundations such as Ford and Carnegie constitute "a virtual invisible government," he says.

    "They are the consultants to the changing of America," Mr. Kent says. "The last serious effort at congressional oversight of these so-called charitable groups was in the 1950s. They have been increasingly running amok ever since."

    For nearly two years, Mr. Kent has researched Internal Revenue Service records and other sources to document the agenda supported by major foundations. Among his findings:

     The Ford Foundation, with assets of more than $9 billion, has given millions of dollars worth of grants to Palestinian groups, including some accused of supporting terrorism. The foundation was also "prime underwriter" of a September 2001 U.N. World Conference Against Racism, held in South Africa, where Israel was denounced as a "racist, apartheid state."

     The environmental movement is heavily subsidized by major foundations. Greenpeace, for example, has received funding from the Rockefeller Brothers Fund, the John D. and Catherine T. MacArthur Foundation, the Bauman Family Foundation, the Nathan Cummings Foundation, the Scherman Foundation and the Turner Foundation.

     With more than $7 billion in assets, the William and Flora Hewlett Foundation — funded by the fortune of the co-founder of the Hewlett-Packard computer company — has made grants to such organizations as the American Civil Liberties Union (ACLU), the Sexuality Information and Education Council of the United States, and "pro-illegal immigration" groups including the Mexican American Legal Defense and Education Fund.

     George Soros’ Open Society Institute, with assets of more than $300 million, has supported the ACLU, the National Organization for Women and the "pro-illegal alien" National Immigration Forum.

    Mr. Kent credits — a Web site started by conservative activist David Horowitz — with inspiring his book. "I got fired up reading … how this foundation money is being poured into anti-Americanism," he says.

    While there are conservative foundations, Mr. Kent says, their assets and donations are a fraction of the liberal foundations.

    Beyond concerns over political activism, however, billions of dollars "that could be going for the betterment of America’s health and education systems" are being wasted by these tax-exempt groups, Mr. Kent said.

    "This concern should cut across all partisan and ideological lines," he said.

    Mr. Kent traces his interest in politics back to elementary school, when, he says, "my dad handed me a Barry Goldwater for president button to wear" during the 1964 presidential campaign. He continued to be involved in politics at the University of Georgia, where he served as state chairman of Young Americans for Freedom.

    For nearly a quarter-century, Mr. Kent worked for the Augusta (Ga.) Chronicle, interrupted only by a two-year stint (1981-82) as press secretary for Sen. Strom Thurmond, South Carolina Republican.

    After serving two years as president of the Southeast Legal Foundation, in 2003 he founded Phil Kent Consulting in order to "be my own boss," he says.

    In addition to several corporate clients, Mr. Kent is also a consultant to Arlington-based Pro English (which advocates English as the official U.S. language) and to Monterrey, Va.-based Americans for Immigration Control. He is a regular panelist on "The Georgia Gang," an Atlanta public-affairs TV show, and has appeared on Fox News, CNN and MSNBC.

    "Journalism opened a lot of doors for me," Mr. Kent says. He has interviewed the past five presidents — Jimmy Carter, Ronald Reagan, Bill Clinton and both Bushes — and counts among his friends former House Speaker Newt Gingrich, former Attorney General Edwin Meese and former Sen. Zell Miller.

    "Networking and friendships have got me where I am today," he says. "Since I moved to Atlanta in 2001, I’ve packed in 15 years of normal networking into five."

    After holding court for several hours at the Buckhead restaurant, Mr. Kent said his farewells, explaining that he has been invited to a party that evening and he wouldn’t want to miss Donald Trump.