How free speech protections fuel civil rights movements.

Milo Yiannopoulos trades on outrage. He is a professional provocateur who has turned insulting different groups of people into a specialty.

He has claimed that the very existence of transgender people is the product of delusional thinking. He has compared Black Lives Matter activists to the KKK. And he has fostered both anti-Muslim bias and disdain for women in one breath, characterizing abortion as "so clearly bad for women's health that it falls second only to Islam.”

Here at the ACLU, we vehemently disagree with Mr. Yiannopoulos’ views. We work hard, every day, with the very communities he targets, to fight for equal rights and dignity for all. We recognize that his words cause grievous pain to many individuals, their families, and their loved ones. Speech like his hurts.

Yet even though we know how wrong-headed Mr. Yiannopoulos’ speech is, the ACLU today filed a lawsuit to defend his free speech rights.

Say what?

We did not take this decision lightly. We understand the pain caused by Mr. Yiannopoulos’ views. We also understand the importance of the principles we seek to defend.

The constitutional principle here, of course, is that government can’t censor our speech just because it doesn’t like what we say. But we’re not representing Mr. Yiannopoulos just out of an abstract principle. We’re also representing him because free speech is crucial to progress in civil rights movements.

Without free speech protections, all civil rights advocacy could be shut down by the people in power, precisely because government doesn’t agree with the ideas activists advance. That was true of the civil rights fights of the past, it’s true of the movements facing pitched battles today, and it will be true of the movements of the future that are still striving to be heard.

The case we filed today is a good illustration of what we mean. The Washington Metropolitan Area Transit Authority, a government agency, prohibits any advertisements on its trains or buses that attempt to “influence members of the public regarding an issue on which there are varying opinions.” Enforcing that rule, the WMATA told the ACLU that we couldn’t put up ads that show the text of the First Amendment (yes, really) in English, Spanish, and Arabic. It also refused ads from People for the Ethical Treatment of Animals (PETA) urging people not to eat meat and another one from Carafem, a non-profit that provides abortion care and family planning services. In Mr. Yiannopoulos’ case, it pulled ads for his book from its trains after passengers complained.

That’s quite a range of views that government decided to silence — from an organization promoting free speech, another advocating for reproductive health care, another urging protection of animals, and another peddling what the ACLU believes to be anti-trans, anti-Black, anti-woman, and anti-Muslim views. That speaks to a core premise of the First Amendment: If government can shut down one of those views, it can shut down all of them. And that would make it harder for any of us to engage in debate with the public and to try to change people’s minds about the issues that are dearest to our hearts.

Protecting the First Amendment rights of all of these speakers is crucial to the ability of civil rights movements to make the change we need to make. When we’re talking about oppressed groups espousing what are often minority viewpoints, the danger of being censored is not just theoretical, it happens all the time. Fighting against that censorship is part of how we ensure that the voices of the marginalized do not disappear from public view.

Consider the movement for LGBT rights. In 2010, a Mississippi high school student, Constance McMillen, wanted to take her girlfriend to the prom and wear a tuxedo. Both acts were inherently expressive, communicating that she’s a lesbian and challenging gender norms. The school said no, asserting they needed to protect other students from these “disruptive” statements. But a lawsuit we brought under the First Amendment ensured Constance could attend prom — as her true self.

In Delaware, Kai Short knew he was male from an early age, despite being assigned female at birth and given a traditionally female name. While incarcerated, the state barred him from legally changing his name, but he argued that the First Amendment protected his right to do so. Delaware ultimately changed the law, allowing Kai to be recognized as his authentic self.

If government can shut down one of those views, it can shut down all of them.

The First Amendment has also repeatedly ensured that advocates could organize and get their messages of protest out in support of the civil rights movement. The Supreme Court relied on the First Amendment when it ensured that the NAACP could disseminate its message through an economic boycott of racist businesses in Mississippi. And when Alabama tried to intimidate NAACP members — and effectively destroy the NAACP itself — by subpoenaing its membership records and exposing its members to retaliation by the state, the First Amendment shut it down.

The fight for women’s rights has also relied on free speech protections. When Virginia made it a crime to publish an ad stating, "Unwanted Pregnancy – Let Us Help You. Abortions are now legal in New York," it was the First Amendment that protected the right of the public to receive such information. And in litigation now ongoing, it is the First Amendment that enables us to challenge an Indiana law prohibiting abortion providers from telling teens seeking abortions without parental consent about their options in other states.

I could go on, but you get the point. In each of these cases, the Constitution's guarantee that we can speak our minds, regardless of what the government thinks about our views, has been crucial to our ability to be out about who we are and what we believe, to share our stories, and to build public support for our equality, dignity, and survival. Allowing government the leeway to "protect" others from our views silences us. And silence means an end to the progress we have been making across a wide range of issues, all over the country.

Some people may say that Mr. Yiannopoulos’ offensive speech sets him apart and doesn’t deserve to be defended. But the sad reality is that many people think that speech about sexuality, gender identity, or abortion is over the line as well. They’ll say that abortion is murder, civil rights advocates are criminals, or LGBT advocates are trying to recruit children into deviant and perverse lifestyles. If First Amendment protections are eroded at any level, it's not hard to imagine the government successfully pushing one or more of those arguments in court.

That means that we, as a country and a community, have to put up with a hefty dose of pain from people like Milo Yiannopoulos. But ask Constance McMillen, the NAACP, and women across the country if the First Amendment has advanced their equality. We think so, which is why we need to keep protecting it.