President Barack Obama surprised many voters during a pre-election interview when he approvingly noted that Ronald Reagan had “changed the trajectory of America” in a way that other presidents had not. In effect, Obama was saying that he, too, aimed to transform America in some fundamental way. Yet while Americans in 1982 may have been divided over Reagan’s politics, at least they knew what he stood for. Do we really understand Obama’s vision for our country?

In his controversial new book, veteran journalist Stanley Kurtz culls together two years of investigations from archives and never-before-tapped sources to present an exhaustively-researched exposÉ of President Obama’s biggest secret-the socialist convictions and tactical ruthlessness he has long swept under the rug.

A personable figure, a thoughtful politician, and an inspiring orator, Obama has hidden his core political beliefs from the American people-sometimes by directly misrepresenting his past and sometimes by omitting or parceling out damaging information to disguise its real importance. The president presents himself as a post-ideological pragmatist, yet his current policies grow directly from the nexus of socialist associates and theories that has shaped him throughout his adult life.

Kurtz makes an in-depth exploration of the president’s connections to radical groups such as ACORN, UNO of Chicago, the Midwest Academy, and the Socialist Scholars Conferences. He explains what modern “stealth” socialism is, how it has changed, and how it continues to influence the Democratic Party. He sheds light on what the New York Times called a “lost chapter” of the president’s life-his years at Columbia—and proves that Obama’s youthful infatuation with socialism was not just a phase. Those ideas have shaped his political views and set the groundwork for the long-term strategy of his administration.

It could be argued that Obama’s past no longer matters, but, in a sense, it matters more than the present. Obama has adopted the gradualist socialist strategy of his mentors, seeking to combine comprehensive government regulation of private businesses with a steadily enlarging public sector. Eventually, in his hands, capitalist America could resemble a socialist-inspired Scandinavian welfare state.

The gap between inner conviction and public relations in Obama’s case is vastly wider than for most American politicians. If Americans understood in 2008 the facts Kurtz reveals in this shocking political biography , Obama would not be president today. The fears of his harshest critics are justified: our Commander-in- Chief is a Radical-in-Chief.