Gwen Ifill, a familiar face to audiences of PBS’ “Washington Week” and “The NewsHour with Jim Lehrer,” has just published her first book, “The Break-Through: Politics and Race in the Age of Obama.”

I may be biased, because Gwen is a good friend and a former Washington Post colleague, but I found this volume the best available guide to the many puzzles of what some have (mistakenly) called “post-racial politics.”

Its greatest strength is reportorial. Well before Barack Obama set out to win the presidency, Ifill began interviewing not just Obama, but the dozens of his contemporaries who had won offices as mayors, governors and members of Congress. She asked where they came from, what fueled their ambition, how they won (often in majority-white constituencies) and how they juggled the conflicting demands on them.

She also revisited many of the surviving icons of the civil rights struggle, drawing useful contrasts between the two generations of black leaders. Almost 30 years ago, I had attempted the same thing myself in a chapter on black leaders in a book called “Changing of the Guard.” Where we overlapped, as with Rep. John Lewis of Georgia, a hero to both of us, I could see that Ifill’s portrait was more insightful and nuanced than my own.

She is at her best in her analyses of some of the “Joshua generation,” to use Obama’s term, figures who are not yet well-known nationally, people such as Massachusetts Gov. Deval Patrick, Newark, N.J., Mayor Cory Booker and Rep. Artur Davis of Birmingham, Ala. She gets all of them to talk candidly and reflectively about their experiences, good and bad.

Viewing Obama in the context of these young leaders — and they all know each other — does not diminish his remarkable accomplishments. But it allows you to see the phenomenon that is Obama in a broader perspective and to believe that he is a harbinger of changes still to come.

Ifill is skeptical — and properly so — that Obama’s election victory signals America’s entry into some mythical “post-racial” society. The politicians she is writing about know better. Race was an issue in every one of their campaigns as they vied for both black and white votes. “As countless new black leaders have discovered,” Ifill writes, “the key to breaking through often lies in just such a crossover — putting whites at ease without alienating blacks.”

That is certainly what Obama did — and what he continues to do as president. Neither his Cabinet nor his White House staff is dominated by African-Americans. But they can be found in some crucial positions, with Eric Holder as attorney general and Valerie Jarrett riding herd on domestic policy.

Obama understood that the key to winning white voters was to make it clear that he was not running as “the black candidate,” in the way that Jesse Jackson and Al Sharpton had done. And he understood that the way to persuade black voters to abandon their early support for Hillary Clinton was to demonstrate enough white-voter strength, as he did in Iowa, so that blacks understood he could actually win.

That was far different from pretending that race does not matter. Ifill writes: “Perhaps a wholesale shift in racial understanding was too much to hope for in a single electoral cycle. But then, again, what did happen was no small thing. Americans were willing to place a widespread acceptance of African-American culture, previously limited to arts, letters, sports and entertainment, into a broad political context.”

The lesson of that Obama victory and the other breakthroughs Ifill writes about will continue to spread. You can see it in Michael Steele’s successful run for chairman of the Republican National Committee and in Artur Davis’ bid to become governor of Alabama.

The ceiling has been lifted on African-Americans’ level of aspiration and accomplishment, and, so far, white voters seem to welcome that fact almost as much as do African-Americans.

As the boundaries expand, the issues facing black politicians become more complex, not easier, starting with the question of what special obligation, if any, they owe to their African-American constituents.

All that, and more, Ifill illuminates in her fine first book.