The day after inauguration, tens of thousands of people — maybe more — led by a group of four women, are marching in Washington, DC. and around the country. Their goal, although they’re not officially pitching it as such, is to send a message about women’s rights that will provide a counterbalance to the political and personal values espoused by incoming President Donald J. Trump.

And by "women’s rights," organizers have taken care to make it clear that they mean all women of all backgrounds: The official platform the Women’s March on Washington places the demonstration in the context of not only suffragists and abolitionists but the civil right movement, the American Indian movement, and Black Lives Matter.

Just two paragraphs into the four-page document, they note that "women have intersecting identities and are therefore impacted by a multitude of social justice and human rights issues." Examples of this, including the especially urgent need for equal pay among women of color and the way they’re uniquely victimized by the criminal justice system, follow in the rest of the platform.

Sounds reasonable, right? But it’s that idea of "intersecting identities" that’s been at the core of criticism of the march, both by would-be participants and by conservative critics.

The New York Times reported that some white women opted out of the march because they felt uneasy, excluded, or attacked by discussions in the Facebook group about what organizers said was a deliberate decision to highlight the unique issues faced by women who are also members of racial minority groups or immigrants.

National Review characterized that dynamic in a dramatic headline, "Women’s March Morphs Into Intersectional Torture Chamber," calling the idea of intersectionality itself "a cliché" that "sounds like one of the reasons we got Donald Trump."

These reactions reflect an ongoing debate about intersectional feminism — the idea that many women are members of other marginalized groups, which affects their experiences — that is bigger than the march. The issue has especially heated up since social media has democratized and made public conversations about issues affecting women.

Critics of the concept often seem to conflate the principle itself with the personal and emotional fallouts that can occur when nonwhite women jump into the debate and push for feminist activists and organizations to include their perspectives.

Other popular anti-intersectionality arguments may sound familiar: that it promotes victimhood, that it causes infighting, or that it’s no more than an invention of out-of-touch, whiny people on college campuses. That’s because they’re the very same criticisms that could be made, and have been made, about feminism itself — or anti-racism, or any other push for equality. In each of these contexts, the pushback tends to come from those who’ve been included all along and think efforts to include others aren’t worth the messiness and fuss.

Intersectionality: a big, controversial word with a simple, tough-to-argue-with meaning

Although intersectionality can be used as a framework for understanding any combination of experiences, you’ll most often hear it in the context of feminism, and that’s obviously why it’s being discussed and debated around the women’s march. Here, it means paying attention to the ways the gender-based discrimination and oppression a woman may experience can be compounded by her race, socioeconomic status, sexual orientation, and more.

"Intersectionality simply means that there are lots of different parts to our womanhood," Brittney Cooper, an assistant professor of women’s and gender studies and Africana studies at Rutgers University, explained. "And those parts — race, gender, sexuality, and religion, and ability — are not incidental or auxiliary. They matter politically."

Lehigh University's Monica Miller defined it in an unpublished 2014 interview with Vox: "An intersectional feminist approach understands that categories of identity and difference cannot be separated and doesn't abandon one category of analysis such as gender, or sexuality in favor of (over)analyzing others such as race, and class."

When the word "intersectionality" has been used in the media recently, it’s often been to explain things like why some white women in social media conversations about feminism have been "asked to check their privilege" — a demand that many see as unfair and aggravating. But the concept is much more than a trump card in Twitter battles — it has deep intellectual roots and real-life consequences.

If you think this started with the Women’s March, or with Twitter battles over "check your privilege," think back a few decades

Kimberlé Crenshaw, a law professor at both UCLA and Columbia, is credited with coining the term intersectionality. She did this in her 1989 paper "Demarginalizing the Intersection of Race and Sex: A Black Feminist Critique of Antidiscrimination Doctrine, Feminist Theory, and Antiracist Politics."

In that article, she talked about the way black women were excluded from both mainstream anti-racist theory and feminist theory. She made clear that this exclusion couldn’t be remedied "simply by including Black women in an already established analytical structure." Because the intersectional experience is greater than the sum of racism and sexism, she said, "any analysis that does not take intersectionality into account cannot sufficiently address the particular manner in which Black women are subordinated."

In other words, explaining black women’s experience was not something that would happen by simply remembering to include them in discussions on racism and sexism. That’s because where these two types of discrimination intersected in their lives, it created something else altogether that deserved its own attention.

To understand how Crenshaw came up with this, remember she was on the legal team representing Anita Hill when she testified that then–Supreme Court justice nominee Clarence Thomas had sexually harassed her in the past. Crenshaw has said Hill’s experience and public reception to the hearings crystallized the complications of race and gender for her.

In an August 2014 interview with the New Statesman, she recalled that many African Americans supported Thomas, agreeing that he was the victim of a "high-tech lynching," while many white feminists took up for Hill but saw her as "a colorless woman," not acknowledging the way being black was part of her experience. It frustrated Crenshaw.

"We as African-American women feminists were trying to say, ‘You cannot talk about this just in gender terms — you have to be intersectional — there is a long history you cannot ignore,’ but they didn't have the skills to be able to talk about it," she said.

Crenshaw also pointed out that she came up with intersectionality to address a specific legal problem: As she put it, "To capture the applicability of black feminism to anti-discrimination law." An example she frequently cites in explaining the need for intersectionality is the 1976 case Degraffenreid v. General Motors, in which five black women sued General Motors for both race and gender discrimination. The law was inadequate to address this, Crenshaw said, explaining, "The particular challenge in the law was one that was grounded in the fact that anti-discrimination law looks at race and gender separately."

The consequence, she said, is that "when African-American women or any other women of color experience either compound or overlapping discrimination, the law initially just was not there to come to their defense." Intersectionality, she said, was a way of addressing the court's blind spot.

In a recent article on the racial dynamics of the women’s march, the New York Times wrote, "This brand of feminism — frequently referred to as "intersectionality" — asks white women to acknowledge that they have had it easier." But while that may be a side effect, intersectionality has a much longer history and a bigger purpose than getting people to admit things.

Crenshaw, who has made it clear that she popularized the term "intersectionality" but not the concept, wrote, "In every generation and in every intellectual sphere and in every political moment, there have been African-American women who have articulated the need to think and talk about race through a lens that looks at gender, or think and talk about feminism through a lens that looks at race."

We hear about intersectionality mostly when someone forgets to think about it

The word "Intersectionality" itself isn’t important — but the concept behind it is. Without it, there’s no way to talk about the experience of people who belong to more than one oppressed group. At its most simple, in the feminist context, it means recognizing that not all women are white, and some LGBTQ people and people of color are women. That’s not controversial, really — it’s just reality.

This helps explain why it mostly comes up in public debates when it’s missing, and when this missing analysis means some people (normally women of color) have been ignored. This is similar to the way we often hear about feminist critiques in response to examples of misogyny flares up or when efforts to make things equal for women fall short.

To give a couple of examples: Patricia Arquette and Madonna each made statements about women’s rights in recent years that seemed to put women and people of color in separate categories. Their remarks provided examples of the very opposite of intersectionality.

In her acceptance speech for winning Best Supporting Actress during the 2015 Academy Awards, Patricia Arquette had this to say about feminism:

It’s time for women. Equal means equal. The truth is the older women get, the less money they make. The highest percentage of children living in poverty are in female-headed households. It’s inexcusable that we go around the world and we talk about equal rights for women in other countries and we don’t ... have equal rights for women in America and we don't because when they wrote the Constitution, they didn't intend it for women. One of those superior court justices said two years ago in a law speech at a university that we don’t have equal rights for women in America and we don’t because when they wrote the Constitution, they didn’t intend it for women. So the truth is even though we sort of feel like we have equal rights in America right under the surface there are huge issues at play that really do affect women. It’s time for all the women in America, and all the men that love women and all the gay people and all the people of color that we’ve all fought for to fight for us now.

Well, this started off okay. But wait a minute, what was that about gay people and people of color whom women have fought for, fighting for them? That makes it seem like these groups don’t include women.

Plus, as Slate’s Amanda Marcotte pointed out in response to the comments, the very issue of wage inequality is affected by race as much as gender:

The American Association of University Women analyzed census data on the wage gap and found that although white women make 78 cents to a white man's dollar in the United States, black women make a mere 64 cents, and Latina women make a paltry 54 cents. Similarly, being gay or transgender often means taking a hit in income. The Center for American Progress finds that same-sex couples raising children make about 20 percent less than straight couples in the same situation. Transgender people have a poverty rate that is four times that of the general population. It is definitely not time for "all the gay people" and "all the people of color" to set aside their own battle for equality in order to fight for straight, white women now.

Not to mention this also seems to imply that the women who have been doing the fighting all along didn’t include women of color and queer women. But that’s what happens when you don't remember that many people often belong to more than one group.

It didn’t make a lot of sense, and when observers said it ignored intersectionality, that’s what they were referring to. But then, providing another example of what not do to, Madonna made a similar statement in a March 2014 interview with Out magazine:

"Gay rights are way more advanced than women’s rights. People are a lot more open-minded to the gay community than they are to women, period." For women, she feels, the situation has hardly improved since 1983. "It’s moved along for the gay community, for the African-American community, but women are still just trading on their ass. To me, the last great frontier is women."

Again, this is confusing and seems to represent a world in which there aren’t gay women, or black women, or feminists who are black and gay. She’s asserting the only women are white and straight, which is the opposite of intersectionality.

There are endless pop culture and political debates that are easier to talk about if we remember that people have multiple, intersecting identities that color their experiences and our reactions to them. Miller said understanding criticisms of Beyoncé as being too sexy to be "properly" feminist, politically contested dialogues around the over-masculinization of the "Black Lives Matter" discourse, and disproportionate levels of white American sympathy over the Charlie Hebdo tragedy compared with outrage over the actions of Boko Haram’s kidnapping and abuse of a group of girls, are all examples of issues that require us to consider the ways different categories of identity work together.

Some people worry that by pushing for feminist analysis to include race, sexuality, class, and other identities, people who push for intersectionality are spreading feminism so thin that it will be useless. But that’s not the case. The problem with this thinking, as Jarune Uwujaren and Jamie Utt, writing for Everyday Feminism, pointed out, is "a one-size-fits-all feminist movement that focuses only on the common ground between women is erasing rather than inclusive. Even if all women deal with sexism, not all women deal with racialized sexism, or transmisogyny, or cissexism."

Some of the angst over the term is about the concept itself; even more is about the tone of social media conversations about it

Christina H. Sommers, resident scholar at the American Enterprise Institute and host of the video blog The Factual Feminist, has a YouTube video centered on her view that intersectionality is no more than "a conspiracy theory that leads to tribalism and bullying." In it, she enumerates what she sees as the consequences of intersectional analysis in feminist groups and organizations: victimization, creation of new reasons for anger, bullying of white men, and new divisions rather than unity.

These are, ironically, some of the same things that critics say about feminism itself: that it encourages women to think of themselves as weak and causes unnecessary, silly conflict.

Cooper says the anti-intersectionality arguments like Sommers’s are familiar. "Some of this is willful ignorance. Surely folks know that it’s racism that is divisive, not those who call out racism," she said. "But there is also a desire for an easy narrative of unity, and easy unity isn't unity at all. That's why it falls apart so quickly."

Cooper’s "easy unity isn’t unity at all" point shed light, for example, on some reactions to the Pantsuit Nation Facebook group that now has more than 3 million members. That online community, formed to harness feminist excitement around Hillary Clinton’s presidential run, flourished after her loss with personal testimonies about girl power, inclusiveness, and good deeds. It succeeded in being an online sanctuary and source of inspiration for many, and inspired enough material for a book proposal. But as Erin Gloria Ryan reported for the Daily Beast, when women of color in the group noted their discomfort with what they saw as the "self-congratulatory" tone of the posts primarily by white women, they said they were "ignored or shouted down for interfering with the humming positivity machine."

Even more common than criticisms of intersectionality like Sommers’s are those that conflate the concept of intersectionality itself with the discomfort experienced by some of the people who find themselves confronted with it on social media.

Writing for the Nation in 2014, Michelle Goldberg reported on what she characterized as "pile-ons about alleged racial insensitivity" and explained her assessment that online, "intersectionality is overwhelmingly about chastisement and rooting out individual sin." The piece, "Toxic Twitter Wars," was all about the internet.

This is a theme. It’s no surprise that National Review’s and New York Times’s pieces on the debate about intersectionality around the women’s march based their reporting in one place: the event’s Facebook page. Social media means, unlike in the pre-internet days when Crenshaw coined "intersectionality," nonwhite women can weigh in, in real time, about how the principle is — and isn’t — being integrated into feminist work. This isn’t always easy to hear.

As a result, many critiques of intersectionality itself are mixed up with the critiques of the tenor and tone of the online discussion about it, and the feelings that accompany those debates. But nothing new is really happening except that new platforms allow nonwhite women to interact with their white counterparts in easily accessible and public ways that they haven’t until now.

When it comes to the women’s march and feminism overall, working this out is worth the potential hurt feelings

Upset and discomfort are predictable parts of debates about intersectionality, says Cooper, who explained, "No one wants to feel like a bad person. Finding out that you might be harming people simply because you have been oblivious to them and their needs is a hard truth to confront."

But hurt feelings and discomfort, primarily experienced online, that come with making sure efforts like the march represent all women are worth it, according to the organizers.

"This was an opportunity to take the conversation to the deep places," said Linda Sarsour, a Muslim who heads the Arab American Association of New York and one of four co-chairs of the national march, told the New York Times. "Sometimes you are going to upset people."

"If your short-term goal is to get as many people as possible at the march, maybe you don’t want to alienate people," Anne Valk, the author of Radical Sisters, said in the same article. "But if your longer-term goal is to use the march as a catalyst for progressive social and political change, then that has to include thinking about race and class privilege."

Cooper says a key point to remember amid debates about intersectionality is simply that "when we organize under the banner of shared womanhood, acknowledging all these moving parts makes our collective work not weaker but stronger."