Liberal feminists need to decide which they value more: ideological purity or political victory.

For the second time in as many weeks, a controversy has broken out over who should be included in the Women's March on Washington, the protest scheduled for Saturday, the day after Donald Trump's presidential inauguration. Last week The New York Times reported that some white women were being made to feel unwelcome at the march by demands that they "check their privilege" and "listen more and talk less" when non-white women speak about the unique burdens they face as members of not just one but of two or more oppressed groups.

And now an article by The Atlantic's Emma Green about the participation of pro-life women in the march has provoked such a fury among leading liberal feminists that organizers have removed a pro-life group (New Wave Feminists) from the march's list of hundreds of "partners." The reason? March organizers say their "platform is pro-choice" so an "error" was made in inviting the pro-life group to be a partner.

Others expanded on the explanation. Writer Amanda Marcotte tweeted that "you cannot be anti-choice and feminist" and that opposing abortion is a "misogynist act." Author Jessica Valenti was likewise "horrified" to hear about the involvement of a pro-life group in the march because "feminism is a movement for justice — [and] abortion access is central."

It is probably the case that most of the women planning to travel to the nation's capital for the purpose of participating in the march are pro-choice. Many of them probably also agree with Marcotte and Valenti in defining feminism in terms of absolute support for abortion rights. But of course, millions of pro-life American women don't define feminism this way at all. Some of them (a "few hundred," according to Green's piece in The Atlantic) were so appalled by Donald Trump's statements about and alleged behavior toward women that they planned to join the march in an act of solidarity with women from all walks of life, races, creeds, faiths, colors, classes, and ideologies.

Does it make sense for march organizers and supporters to urge such women to stay home? Or to ensure that if they do attend, they will be treated with contempt for espousing a version of feminism that's defective, oxymoronic, and awash in false consciousness and self-loathing?

I think pro-life women deserve far more respect than this, but that's beside the point. I'm a man and so a good number of pro-choice feminists will dismiss out of hand anything I say on the subject.

What they may find more difficult to wave away is the suggestion that they begin thinking more like people out to build a successful political movement and force of opposition to the incoming president and his party in Congress, and less like members of a factional ideological sect.

In a democracy, successful political movements go broad. They are ecumenical, seeking to bring as many people as possible into an inclusive coalition, because that's how elections are won and mandates are forged, and because they understand that politics involves compromise and building bridges of partial agreement and commonality with those who disagree on some important issues but not on others. (Pro-life feminists tell Green that they've been inspired to attend the march by "cultural misogyny, the state of education and health care, and a desire for their own daughters to be able to lead.")

Sects (whether political or religious) have different priorities — like upholding ideological purity, enforcing conformity to official doctrine, policing the boundaries of acceptable opinion, and excommunicating those who fail to toe the party line. They prefer losing to compromising their principles.

When a march has hundreds of partners, what harm is done by including a single organization that opposes abortion? When many thousands plan to march in a rally of solidarity, why express disgust at a few hundred who dissent from the views that overwhelmingly dominate the event? When the rise of Donald Trump may be shattering the bonds that have tied so many pro-life women to the Republican Party, why not do everything possible to encourage these women to make a complete break and join the opposition?

The pursuit of political self-interest points in the opposite direction from the one taken in response to Green's story. Which means that march organizers and their allies aren't pursuing their political self-interest. They're acting like ideological commissars.

Enforcing standards of purity can be rewarding in all kinds of ways. But winning a hard-fought political contest usually isn't one of them.