Michael Kazin’s most recent book is American Dreamers: How the Left Changed a Nation. He is co-editor of Dissent and teaches history at Georgetown University.

Contrary to what everyone who loved—or hated—his inaugural address seems to think, President Obama has yet to demonstrate that he is determined to launch a new liberal era.

The big speech did gesture in that direction. Obama declared, in the style of FDR, that “our country cannot succeed when a shrinking few do very well and a growing many barely make it.” The line about equality being “the star that guides us still; just as it guided our forebears through Seneca Falls, and Selma, and Stonewall” was a welcome salute to three of the most prominent civil rights movements in American history. And not since Lyndon Johnson has a president spoken about poverty with such apparent conviction and specificity: “We are true to our creed when a little girl born into the bleakest poverty knows that she has the same chance to succeed as anybody else, because she is an American; she is free, and she is equal, not just in the eyes of God but also in our own.”

But to believe that Obama has truly revived the great tradition of egalitarian reform is to neglect the distinction between two species of modern liberalism: that which promotes the equality of rights and that which works toward a greater equality of opportunity and wealth. The latter, the social variety, emerged from the class tumult of the Gilded Age and inspired such key New Deal measures as Social Security, the WPA, and the National Labor Relations Act. The former harks back to the abolitionists and early feminists; it demands that the promise of individual liberty be extended to every American, regardless of their skin color, national origin, gender, or whom they happen to love....