The op-ed below by Jeanne Allen appeared in the Wall Street Journal print edition on August 17th, 2017.

Randi Weingarten, the leader of the American Federation of Teachers, has insulted millions of students and families. In a speech at a union conference last month, Ms. Weingarten claimed that the school-choice movement has its roots in 1960s-era racism. Charter schools and vouchers, she asserted, “are only slightly more polite cousins of segregation.”

This is a blatant attempt to rewrite history. The modern education-reform movement was originally propelled by African-Americans and progressives. Fannie Lewis, a Cleveland councilwoman and grandmother, fought for the Cleveland Scholarship Program that was enacted in 1995. Polly Williams, a Wisconsin state representative, helped push through Milwaukee’s early school-choice program in 1990.

Williams, a Democrat and former Black Panther, found few allies for school choice among her natural constituencies. But she firmly believed something had to be done to help children in failing schools. So she joined a diverse coalition, including conservative Gov. Tommy Thompson, to launch the Milwaukee program, which is still running strong more than 25 years later.

Ms. Weingarten must know these facts, because they have been exhaustively chronicled. Yet she actively hides and obfuscates this history. What’s really motivating her over-the-top rhetoric? The answer lies in the numbers. While thousands of children are on waiting lists for charter schools, the AFT’s membership is in decline. As the union’s head count drops, so does its political clout.

Figures compiled by union-watcher Mike Antonucci show the seriousness of the situation Ms. Weingarten faces. The AFT routinely claims it has 1.6 million members, but that number, Mr. Antonucci says, “is not strictly accurate.” Here’s his math: He cites U.S. Labor Department filings that show the AFT reported 1,544,143 members last year. More than 600,000 of them belonged to affiliates that are merged with the National Education Association, the other big American teachers union. Although both the AFT and NEA count these people as full members, the two unions must split their dues.

Mr. Antonucci further says that nearly 357,000 AFT members are retired, meaning they pay no dues. Another 330,000 members work only part time. “The bottom line: AFT’s 1.6 million members equate to a dues-paying equivalent of 854,000 full-time employed teachers,” he writes.

Ms. Weingarten likes to style herself as a defender of the urban poor, but her recommendations for education tell another story. Her primary concern seems to be self-preservation. But the biggest threat to her power and position won’t be from the Trump administration or school-choice advocates. It will be from AFT members who recognize that she’s undermining the union’s credibility for her own gain.

Ms. Allen is the founder and CEO of the Washington-based Center for Education Reform.