President Donald Trump has bulldozed a lot of our expectations about how a president is supposed to act. We expect our chief executive to be professional, diplomatic, and poised. But The Donald? Not so much. Like a grumpy toddler, he complains when things don’t go his way and taunts anyone who dares to disagree with him.

Trump often veers into bullying, especially when it comes to strong women who stand up to him. Remember him physically intimidating Hillary Clinton, following her around the stage during the second presidential debate in 2016? Or talking about Megyn Kelly, then of Fox News, having “blood coming out of her wherever”? Or tweeting that MSNBC host Mika Brzezinski was allegedly “bleeding badly from a face-lift” during a visit to one of his resorts?

You won’t be surprised to learn social media harassment disproportionately affects young people, especially girls and women. A 2014 Pew Research Center study found that “women were particularly likely to cite social networking sites and apps as the scene of their most recent incident with online harassment.”

As the president has aptly demonstrated, social media has given bullies of all ages an instant, potentially worldwide stage and the ability to cut people down 140 characters at a time. With our bully-in-chief leading by example, kids across the country are emulating the president’s behavior to target their classmates, particularly those who come from marginalized communities such as immigrants, LGBTQ individuals, and people of color. Being a teen has always been tough. But our digital society has given high school bullies all kinds of new ways to be cruel to others.

Recently, a teenage daughter of a friend found this out firsthand. A groups of kids used social media to gang up on her and make her feel like a total outcast. They invited her into a group Snapchat, only to spend the next hour and a half relentlessly shaming her. Sobbing, she handed off her phone to someone else to escape the cyberbullying.

For me, bullying is personal—and it doesn’t always stay on social media. In 2009, I founded Trust Women, a pro-choice nonprofit that owns and operates clinics that provide abortions in Wichita, Kansas, and Oklahoma City, Oklahoma. Every single day, anti-choice protesters intimidate the people who come to our clinics for help. They threaten me and my staff, and publish our home addresses to make us feel less safe. Even the Kansas legislature is complicit; it makes abortion providers adhere to rules that nobody else has to follow—for example, stipulating what kind of font, color and type size abortion providers can use when providing information to patients.

Bullying—a pattern of aggressive behavior that thrives on a power imbalance—is a form of violence, and it can escalate.

I know that the threats we face from abortion opponents are not just words. My mentor, Dr. George Tiller, was shot and killed by one of those anti-choice protesters while attending church one Sunday.

Bullying can also drive victims to hurt themselves and even contemplate suicide.

We need to stand up to bullying, whether it’s coming from the high school cafeteria or the White House, because it is a matter of life and death.

So, to our president: “Delete your account.” Or stop your cyberbullying. You are hurting your own office, the United States’ reputation, and teens (and adults) across this country every time you tweet something vindictive and hurtful.

To teachers and parents like me: We must model kindness and compassion for our children. It’s up to us to make sure our kids take their cues from us, not from the unpredictable Twitter user who also happens to be our president.

And to teen girls everywhere: You are strong, smart, and powerful. Don’t let anyone make you a victim, either by bullying you or by goading you into bullying others. We can show the leader of our country that we’re better than using the internet to make other people feel small. And it starts with you.