In October 2009, the Obama White House launched a concerted attack against critical press coverage, one unparalleled since the days of the Nixon White House. In one respect, Barack Obama and Richard Nixon were in agreement: both perceived a distinctly liberal bias in the media. Nixon denounced the press for its leftism, Obama objected to the press's deviation from it. So Obama and his senior staff singled out for condemnation Fox News, the lone television network that did not serve up the fawning coverage the president and his team had come to expect.

In “The Silencing: How the Left is Killing Free Speech,” Kirsten Powers recounts that in the space of a few days, White House communications director Anita Dunn, her deputy Dan Pfeiffer, White House Senior Adviser David Axelrod, and White House Chief of Staff Rahm Emmanuel openly asserted that the administration properly excluded Fox reporters from press briefings because Fox was not a legitimate news organization. When asked for comment by NBC News, President Obama stood behind his team.

Grousing about criticism is only human, and presidential displeasure with the press is nothing new. But wielding the presidential bully pulpit to decree what counts as legitimate news coverage represented an ominous turn in American politics.

Separation of press and state is as essential to the American constitutional order as separation of church and state. In one respect, religious freedom depends on press freedom: a press that is answerable to, or in the pocket of, the government will be unwilling to report, or incapable of reporting accurately, when government exceeds its lawfully prescribed boundaries.

What could the president and his advisers have been thinking in orchestrating an assault on Fox News? Where could our president, a graduate of Columbia University and Harvard Law School and a former lecturer at the University of Chicago Law School, have gotten the idea that it was government's prerogative to determine who properly reports the news and to supervise the flow of opinion in the country?

Sad to say, they could have been thinking they were faithfully implementing the ideas about the need to regulate speech that they had learned in college. The smearing of opponents of the progressive party line as purveyors of hatred; the denigration of critics of left-liberal public policy as racists, sexists, and homophobes; and the ostracism of advocates of faith, tradition, and the virtues of America's experiment in self-government as minions of sinister forces—these have become routine features of intellectual life at our leading universities. The development of doctrines designed to curtail nonconforming speech was already well under way by the time Obama attended college in the early1980s and law school in the early 1990s.

This is not to say that all members of the left today are instinctively intolerant and bent on stifling liberty of thought and discussion. Yet all too rare is the contemporary liberal who is instinctively appalled by the contempt for speech emanating from Democratic Party politicians, the university world and elite media, and who is willing to call his or her comrades to account.

Kirsten Powers is one of these rare liberals. In "The Silencing,” she methodically documents—and exposes the hypocrisy, incoherence, and sheer contempt for evidence and argument that underlie—the delegitimization of dissent that has become the stock in trade of what she characterizes as the "illiberal left."

A Fox News contributor and columnist for USA Today and the Daily Beast, Powers grew up in the conservative town of Fairbanks, Alaska, the daughter of politically engaged Democrats who taught her that reasoned debate is the life blood of the truly liberal spirit. "I can't remember anyone ever suggesting that conservative views were illegitimate and unworthy of debate," writes Powers of lively political conversations with her parents in Fairbanks.

“I first encountered that attitude,” she recalls, “when I moved to New York City much later, where bumping into a conservative was less likely than spotting a unicorn.”

It is refreshing to encounter a public intellectual who unapologetically supports the Affordable Care Act while also arguing that “to think that Republicans and conservatives oppose it because the president is black is absurd.” Powers argues—and demonstrates by her admirable example—that devotion to freedom of speech should transcend partisan differences.

The danger today is that defense of freedom of speech is becoming the preserve of conservatives—and thus stamped as a partisan issue. This is bad for both right and left.

Notwithstanding high-minded and compelling conservative arguments on behalf of unfettered exchange of opinion, the fact remains that as a despised minority in the media and the academy, conservatives have a partisan interest in vindicating the principle of freedom of speech. Meanwhile, the identification of freedom of speech with conservatism encourages the conceit among those on the left that liberty of thought and discussion is a negotiable luxury, if not an outright and insufferable impediment to progress.

The crude political calculation that in a liberal democracy one's side will not always control the levers of government power should be enough to persuade citizens of all stripes that the proper response to contrary opinion is not government regulation but joining issue. More sophisticated considerations—that the encounter with opposing points of view exposes unexamined assumptions and errors, enlarges the moral imagination, and in America gives civic expression to the founding belief in the dignity of the individual—should be, along with the crude political calculation, rigorously taught at universities.

In fact, as Powers shows, the opposite is happening. "Campuses across the United States have become ground zero for silencing free speech,” she writes. She immerses readers in the gory details about the institutional mechanisms and Orwellian ideas that universities have crafted to police speech. These include the promulgation of speech codes intended to outlaw the expression of opinion that students or faculty find hurtful; the restriction of unfettered speech to small, carefully demarcated "free speech zones"; the demand for "trigger warnings" on courses, syllabi, and reading materials that might conceivably be emotionally disturbing; encouragement of the idea that "micro-aggressions"—what earlier generations referred to as irritations and annoyances—are both pervasive and debilitating; the shouting down and disinviting of distinguished lecturers who offend campus orthodoxy; and the redefinition of moral and political disagreement as a form of “violence.”

Far from drawing the public's attention to our universities’ war on free speech, the media aid and abet it. To be sure, as Powers points out, the press is having trouble preserving its own freedom. Obama has minimized direct contact with political journalists. The Obama Justice Department has harassed, investigated, and prosecuted reporters; it secretly seized phone records and emails of Fox News reporter James Rosen and phone logs of Associated Press editors and reporters. And, according to a report by former Washington Post executive editor Leonard Downie, the Obama administration launched a "war on leaks and other efforts to control information" that has constituted "the most aggressive" attack on press freedom since Watergate.

Nevertheless, most of the elite media—overwhelmingly left liberal—have largely neglected to cover the left's crusade against free speech. Operating out of newsrooms, as Powers observes, in which "there is nobody to push back on their biases," reporters seem unable to detect anything amiss on campuses, in the media, and in the political arena where, after all, the draconian regulation of speech is intended to serve avowedly left-wing causes.

An increasingly illiberal left, according to Powers, has found a ruthless ally in an increasingly illiberal feminism. To oppose abortion, or to suggest that owners of family businesses should not be required by law to subsidize their employees' purchase of a narrow range of birth control options to which the owners object on religious grounds, or to insist that the accused in campus sexual assault cases be accorded fundamental due process rights is, illiberal feminists declare, to wage “war” on women and to advocate positions that have no place in polite conversation or public debate.

From feminism to the media to the professoriate to the West Wing, the illiberal left has been empowered to curtail freedom of speech by the transformation of liberal education—whose classic purpose was to emancipate the mind and promote toleration—into a means for reproducing progressive dogma and inculcating intolerance of alternative points of view. Because Kirsten Powers is right—our colleges and universities have become ground zero in the fight for freedom of speech—the restoration of free speech depends on the restoration of liberal education.