Former television journalist Campbell Brown has become an advocate for opposing teacher tenure. (Andrew Burton/REUTERS)

Campbell Brown used to host a program on CNN with a tough-sounding subtitle, “No Bias. No Bull.” Brown was an equal-opportunity skeptic — “spunky-yet-shrewd,” as the New York Times once described her — who called out liberals and conservatives alike during her hour on the air each weeknight.

But since the end of her CNN program in 2010, Brown has made an unusual transition. After years as a journalist, steeped in notions of fairness and balance, Brown has transformed into an advocate, taking a very public side in one of the many contentious battles over public education.

Brown, 46, has become an articulate voice and recognizable face opposing tenure, the century-old system of laws and contractual guarantees giving public-school teachers due-process rights in layoffs and terminations. Brown argues that tenure makes it difficult and expensive for school systems to remove underperforming teachers, and it protects their jobs at the expense of their students.

“I’m a mom, and my view of public education begins and ends with the fundamental question: Is this good for children?” Brown says by phone from New York, where she lives. “In a situation where it’s the child or the adult, I’m going with the child. . . . Tenure is permanent lifetime employment. There’s no reason why anyone’s job should become untouchable for the rest of their life.”

Campbell the journalist might interrupt an interview subject to take exception to that kind of generalization. Teachers unions and their advocates say tenure — instituted to prevent widespread abuses of a female-dominated workforce — doesn’t guarantee much beyond a fair hearing. Tenured teachers deemed ineffective or negligent, after hearings and evaluations, are fired, they point out.

“I have trouble with this issue because it’s so totally illogical,” says Diane Ravitch, an education historian. “It’s hard to understand why anyone thinks taking away teachers’ due-process rights will lead to great teachers in every classroom.”

As for Brown, Ravitch is dismissive: “She is a good media figure because of her looks, but she doesn’t seem to know or understand anything about teaching and why tenure matters. . . . I know it sounds sexist to say that she is pretty, but that makes her telegenic, even if what she has to say is total nonsense.”

Brown has raised the issue of tenure in op-eds and on TV programs such as “Morning Joe.” But she may be just getting warmed up. An organization she founded last year, the Partnership for Educational Justice, is spearheading a legal and public-relations campaign against New York state’s tenure law. By month’s end, or thereabouts, lawyers allied with Brown’s group will file a lawsuit modeled on Vergara v. California, which led a California Superior Court judge to strike down the state’s tenure and seniority statutes last month. The court ruled that the laws were unconstitutional because they protected ineffective teachers, especially in high-poverty schools, thus denying poor and minority children an equal education. The ruling has been stayed pending an appeal, but it has raised the hopes of anti-tenure forces across the country.

Brown’s effort is funded by . . . well, that’s not clear. An advocate of transparency and full disclosure as a journalist, Brown won’t say who is backing her nonprofit organization.

“I’m interested in full disclosure for people who give money to politicians,” she says. “But I’m not a politician. I’m an advocate. If someone wants to give money to an [advocacy] organization anonymously because they don’t want to take the flak that may come along with that, I respect that.”

Being on the other side of the questions is new territory for Brown, who not long ago was the one doing the asking.

After a year of teaching after college (she taught English in what was then Czechoslovakia), Brown began climbing the TV-news ladder, working as a local-news reporter at stations in Topeka, Kan.; Richmond; Baltimore; and Washington (WRC, channel 4).

A native of Ferriday, La., Brown joined NBC News in 1996 and began a fast rise. She covered the Pentagon and the White House, as well as George W. Bush’s 2000 presidential campaign. She was eventually named a co-host of the weekend “Today” show and was Brian Williams’s main substitute anchor on the flagship “Nightly News.”

At one point in 2006, she was on the short list to replace Katie Couric as a co-host of the “Today” show. The job went to Meredith Vieira.

CNN poached Brown in 2008 and gave her an eponymous prime-time program. The 8 p.m. time slot was murderous; Brown was up against Fox’s Bill O’Reilly, Keith Olbermann on MSNBC and Nancy Grace on HLN. She also had two children, both boys, with husband Dan Senor, whom Brown had met in Iraq while she was reporting and Senor was serving as spokesman for the Coalition Provisional Authority. (Senor, now an investment banker and columnist, was also an adviser to Mitt Romney’s 2008 and 2012 presidential campaigns and is on the board of StudentsFirstNY, part of the organization founded by former D.C. schools chancellor Michelle Rhee that also favors eliminating tenure.)

By 2010, the combination of two young children at home and her program’s stagnant ratings prompted Brown to leave TV. Despite occasional offers to return, she says she has no interest in appearing on TV as anything other than an advocate.

Brown’s path from journalist to partisan was a relatively short one. Two years after leaving the air, she began writing editorial pieces, including one in the New York Times rapping President Obama for his “paternalistic” attitude toward women during the 2012 campaign and another excoriating Planned Parenthood.

She also had an epiphany of sorts. After encountering stories about the difficulty New York City schools had in firing teachers accused of sexual misconduct — a catch-all term covering inappropriate touching and comments as well as felonious behavior — Brown decided to do something about it. Using her own funds as seed money, she formed the Parents Transparency Project, which aimed to highlight the issue.

Her group eventually raised $100,000 for a TV ad campaign during the city’s mayoral race that asked whether any of the candidates had “the guts to stand up to the teachers’ unions,” which the ad implied had delayed action on 128 cases of misconduct during the preceding five years.

While some teachers accused of misconduct had remained on the job, the ad distorted several aspects of the emotional issue. One is that 33 of them had been fired. The balance were either fined, suspended or transferred for minor, non-criminal complaints. The other was the ad’s implication that the city’s main teachers union, the United Federation of Teachers, had impeded the disciplinary process. As the union pointed out, however, under state law, non-criminal complaints against teachers are handled by independent arbitrators. Neither the union nor the mayor had a say in such cases.

“We have a zero-tolerance policy,” says Dick Riley, a UFT spokesman. “A person guilty of sexual misconduct is and should be fired. They are not automatically fired if there is an allegation, or if they are charged. Campbell Brown seems to believe that an accusation is the same as a conviction.”

Undaunted by the lukewarm reception her campaign received, Brown widened her focus. If state laws protected the jobs of sexual miscreants, she reasoned, it also protected many more who are merely ineffective. She started a new organization, the Partnership for Educational Justice, to fight the tenure issue, absorbing the remnants of her first group.

Teachers unions say Brown’s campaign is draconian and will undermine public education and teacher morale rather than improve them. “Stripping teachers of their voice and support will make it harder” to recruit and retain good teachers, says Randi Weingarten, president of the Washington-based American Federation of Teachers. Brown’s suit, she says, “is just about pitting students against teachers.”

Brown, whose two sons attend a private religious school, would like to see a broader array of public-school “reforms,” from the expansion of charter schools to vouchers and tax credits to fund private- and religious-school tuition. Last week, as keynote speaker at the National Alliance for Public Charter Schools annual conference in Las Vegas, she questioned the wisdom of sticking to what she described as a broken status quo. A crowd of more than a thousand gave her a rousing ovation.

“This is the most rewarding thing I’ve done,” Brown says. “I loved every minute of my life as a journalist. But you can write and report and jump up and down and scream, but at the end of the day, what changes? Having children makes you want to connect with other mothers and do something meaningful and not just be an observer. I felt this is what I was always meant to do.”

As for Ravitch’s slam, Brown learned long ago to roll with those kind of punches.

“I thought we had moved beyond judging women on their looks and yet, once again, Diane is here to give us an education,” she says. “Sadly, what is missed is that this is not about her or me but rather millions of schoolchildren being denied a decent education. When parents stand up and demand something better, I’m proud to stand with them.”