When Pamela Geller and her controversial organization, the American Freedom Defense Initiative, announced it would hold a cartoon contest in Garland, Texas, their plan to satirize and lampoon the founder of Islam was intended to have both a defiant and provocative free-speech edge.

Sunday’s contest and its $10,000 prize were prompted in part by the Paris Charlie Hebdo massacre in January, Ms. Geller said in March, as well as the riots in Muslim countries sparked by the publication of satirical anti-Muhammad cartoons by a Danish newspaper in 2005. And indeed, as if on cue, two gunmen with apparent ties to Islamic militants overseas tried to storm the heavily secured event in a similar fashion, before being shot dead by a local police officer Sunday night.

The incident comes at a time when tensions between some segments of American society and Muslims appear to be becoming more fraught – with protests against Muslims in Texas and anti-Muslim social-media attacks after the release of the film "American Sniper." In that context, Geller's actions raise questions about speech seen by many as motivated to incite anger and hatred.

It is an issue Geller has faced before. Two weeks ago, she won a federal free-speech case against New York’s Metropolitan Transportation Authority, which had refused to put up one of her ads: “Killing Jews is Worship that draws us close to Allah” – a quote the ad attributes to “Hamas MTV.”

Geller’s organization has often clashed with officials in other cities, including Philadelphia and Washington, over their incendiary ads, some of which compare Islam to Nazism. In 2012, another federal judge ruled that cities could not refuse to post her subway poster that read: “In any war between the civilized man and the savage, support the civilized man. Support Israel. Defeat Jihad.”

Many supporters of Geller and her organization view the violence on Sunday as a vindication of their views of Islam as an inherently violence-prone religion. But for others, her relentless campaign to push the boundaries of free speech with intentionally incendiary messages is only poisoning public discourse at a particularly volatile time.

“And coming as it did right when we, the United States of America, are really facing a time when we have to question what it is that holds us together, I can see this potentially aggravating the already-challenging times for dealing with some of these questions about cultural difference, diversity, and what kind of society we want to be,” says Gordon Coonfield, director of graduate studies in communication at Villanova University near Philadelphia. 

After analyzing some of the submissions to the American Freedom Defense Initiative’s “Muhammad Art Exhibit and Cartoon Contest,” Professor Coonfield pointed out the similarities of some of the depictions of the prophet Muhammad to posters for “Der Ewige Jude,” or “The Eternal Jew,” a notorious Nazi propaganda “documentary.”

In one of the cartoons, the prophet is depicted as contorted and snarling and as a hook-nosed man in a turban holding a bloody knife. The caption reads, “When it comes to religion ... I’ve got the edge.” The face, Coonfield notes, is nearly identical to the contorted face of “The Eternal Jew” poster.

“That strategy for creating a sense of ‘unity’ by lifting up this internal enemy is as old as human civilization and culture,” he says. “It’s ironic that the kind of thinking that Hitler used, and the Nazis have become famous for using – propaganda to try to create this sense of a collective by creating a strong unquestionably evil Other who is right here in our midst ... so it’s kind of ironic that she’s trying to link some of these things together, when that is in fact her message.”

Despite the fact that images depicting the prophet Muhammad cut deeply to the heart of Muslim identity, Muslim leaders in Texas told their followers not to picket or protest the event on Sunday.

“Her words are not just free speech,” says Linda Sarsour, executive director of the Arab American Association of New York. “They are inciteful; they incite hate against our whole community. I was very dismayed by the shooting in Garland, Texas, but at the same time, Pamela Geller is not the victim in this situation that we’re in right now.”

“She intentionally put that event together in hopes that she’d get the response that she received,” Ms. Sarsour says.

“We prayed, but not one Muslim from the state of Texas went out to protest her,” she added. “Muslim leaders specifically told people, do not go anywhere near her. Let her do whatever she does. We don’t care. And there was no protesting outside – unfortunately, except for these two guys from Arizona, who were already on the radar of the FBI anyway.”

Advocates have tried to counter Geller’s free political expressions with ad campaigns of a different tone. In 2012, a coalition called Rabbis for Human Rights responded to her “support the civilized man” poster with an opposing message that read, “In the choice between love and hate, choose love. Help stop bigotry against our Muslim neighbors.”

And last week, the makers of the satirical film “The Muslims Are Coming!” launched a humorous series of subway and bus ads to counter Geller's. “The Muslims are coming, and they shall strike with hugs so fierce, you’ll end up calling your grandmother and telling her that you love her.”

But in an era in which the Islamic State, the Tsarnaev trial, and the lingering aftermath of 9/11 still inflame fears about Islam, many worry that Sunday’s violence will exacerbate the current tensions.

“Free speech is about being open to listening to the ideas you hate the most, that you disagree with the most, and I feel this group in particular is hiding behind this free speech rhetoric,” Coonfield says. “This can’t become the poster child for Christianity versus Islam or the West versus the Middle East. We have to maintain a space where groups that have very different ways of thinking and viewing the world can still come together to talk about it, without resorting to this kind of craziness.”