While speaking to reporters on Monday, President Trump defended the use of tear gas on Central American migrants seeking asylum at the border over the weekend, saying that border patrol agents “had to” use it in self-defense.

The use of the gas has angered many critics who noted there were families with young children among the migrants. Images from Sunday show toddlers in diapers screaming and fleeing from the gas with tears streaming down their faces.

When asked by reporters if he was comfortable with the use of tear gas on children, Trump responded: “They had to use [force] because they were being rushed by some very tough people. And they used tear gas. Here’s the bottom line: Nobody’s coming into our country unless they come in legally.”

The migrants had arrived at the San Ysidro border crossing, and hundreds of them rushed toward the fence to try to cross the border. Homeland Security Secretary Kirstjen Nielsen said some of the migrants threw “projectiles” at border agents, according to the Washington Post. U.S. Customs and Border Protection Commissioner Kevin McAleenan also told reporters Monday that some migrants were throwing rocks and otherwise behaving aggressively and the tear gas “prevented a dangerous situation from getting worse.”

As the Post reported, tear gas as a weapon has been banned in warfare in most of the world—some consider it a chemical weapon—and while it is legal for use by law enforcement authorities, it is considered very dangerous to infants and may be harmful to other children.

That has not stopped conservatives from jumping to defend its indiscriminate use as necessary and humane. On Fox & Friends on Monday, Ron Colburn, the president of the Border Patrol Foundation and a former deputy chief for U.S. Border Patrol, said its use was an effective way of “deterring people without long-term harm.” He explained: “To clarify, the type of deterrent they used is OC pepper spray—it’s literally water, pepper, with a small amount of alcohol for evaporation purposes. It’s natural, you could actually put it on your nachos and eat it.”

While it’s still unclear if pepper spray was also used with the tear gas, neither it nor tear gas are harmless if one is exposed. Pepper spray would certainly not be harmless if consumed, and the chemical distilled from chile peppers is several thousand times more concentrated than it would be in food. Children and the elderly are at risk of respiratory issues if sprayed.

Sen. Lindsey Graham turned his attention to Alexandria Ocasio-Cortez, expressing outrage over her tweet that said applying for asylum “isn’t a crime” and compared the migrants to Jews fleeing Nazi Germany and other historical refugees. In his own heavily criticized tweet, Graham chided her: “I recommend she take a tour of the Holocaust Museum in DC. Might help her better understand the differences between the Holocaust and the caravan in Tijuana.”

The response that disgusted Democrats the most came from Fox commentator Tomi Lahren, who tweeted: “Bum-rushing the border is a CHOICE and has consequences. Watching the USA FINALLY defend our borders was the HIGHLIGHT of my Thanksgiving weekend.”

While Colburn’s argument was mocked for its absurdity, Graham’s dismissed as a weak attempt to redirect outrage, and Lahren’s tweet treated as the work of a pundit who peddles in outrage, Trump’s comments rested on a specific cause for the ruthlessness. Not for the first time, Trump cited rock-throwing as a justification for force. In the past, border patrol agents have mentioned rock-throwing as the reason for using lethal force. Just last week, an agent who shot a Mexican teenager 10 times through the border fence in 2012 was acquitted of manslaughter, as his defense argued he was acting on his training and defending himself from the boy. In fact, earlier this year, Trump endorsed using deadly force on migrants who throw rocks. “They want to throw rocks at our military, our military fights back,” he told reporters. “I told them to consider it a rifle. When they throw rocks like what they did to the Mexican military and police, I say consider it a rifle.”

But even if one agreed that rock throwing warranted an aggressive response from border agents, the fact remains: The toddlers who were tear-gassed at the border could not be called anything other than innocent victims.