The Women’s March on Washington in response to President Donald Trump’s inauguration this past Friday, with Business Insider estimating that “approximately 200,000 people will convene … to stand up for gender equality.” Unsurprisingly, that estimate ended up being off by a little bit, and the march wasn’t exclusive to Washington.

Official numbers will be impossible to obtain, but city officials estimate over 500,000 people attended the rally in Washington alone, with nationwide attendance estimates ranging from just over one million to up to 4.6 million. These numbers, without question, make it one of the biggest protests in U.S. history, and — if highest estimates are to be believed — it may be the biggest protest in our nation’s history.

Looking again at the Business Insider article previewing the Women’s March, a common thread is found among the highest-attended protests they list: civil rights.

For context’s sake, the next biggest protest (based on high-end estimates) on their list was the Million Woman March in 1997 that took place in Philadelphia, with an estimated two million protesters attending. The march on Washington in 1963, where Martin Luther King Jr. delivered his “I Have a Dream” speech, had an estimated attendance of 250,000 and the anti-nuclear weapons protest in 1982 at Central Park in New York City had over one million estimated attendees.

There can be several reasons that civil rights issues drive more people out to protest. From speaking to friends who support civil rights activism and protests, they see protesting as a way to be heard; specifically, mass public protest forces oppressive authorities to listen.

Another reason that protests may come hand-in-hand with civil rights issues might be a more obvious one: liberal people in America tend to be younger. Being part of large and aggressive crowds, shouting at cameras, chanting, marching and general disruption of the peace is much more of a young person’s game.

Perhaps the most important factor that matches protesting and civil rights issues is the passion that comes along with fostering change.

Take a quick look at the famous Howard Chandler Christy painting “Scene at the Signing of the Constitution of the United States” and you can see the demographic that made up the most powerful class of people at the time of this nation’s founding. You can see it even more clearly looking at the presidential portraits (with one exception) through our nation’s entire history.

It is no secret that being white, straight, wealthy and male provides immense privilege in our country. Those who fight for the equal treatment of people of color, women, members of the LGBT community and the economically disadvantaged are fighting for a change of the status quo.

Fighting for that change simply breeds more passion than fighting for complacency.

Nicholas Hunter is a columnist, contact him [email protected].