This week, dozens of protesters unfurled banners that read “Aid to Israel = Bombing Palestinians” in the Hart Senate Office Building at the Capitol while chanting “cease-fire now.” Police soon arrested them.

Not far away at the White House, a group of 18 elder Jewish protestors wearing t-shirts that read “not in our name” chained themselves to the fence.

Across the country in Los Angeles, a group of protesters blocked a downtown freeway while wielding a banner calling for a “permanent cease-fire.”

These were only some of the most recent of hundreds of pro-Palestinian and anti-war protests across the United States since the start of the Israel-Hamas war.

This current wave of protests on behalf of Palestinians represents some of the largest on this issue in the United States, where, historically, most Palestinian solidarity activism has existed among some minority communities, university campuses and the political fringe. According to experts who spoke to the PBS NewsHour, this swell of protest is the result of a number of factors, including growing pro-Palestinian sentiment among younger people, the mounting civilian toll in Gaza from Israel’s military response, and more people being drawn into activism through issues like reproductive rights, Black Lives Matter and concerns about democracy.

WATCH: Israel meets renewed resistance from Hamas amid pressure to reduce civilian casualties

The protests, and their messages, have also been criticized by pro-Israel organizations and politicians, some of whom claim the protests are antisemitic. Some in the U.S. have seen the protests as threatening and argue they will contribute to rising anti-Jewish hatred, including on university campuses. Last week, during a Congressional committee hearing, the presidents of three ivy league universities were ensnarled in controversy when they gave “legalistic” answers to a question about whether “calling for the genocide of Jews” violated their policies. One has so far resigned, university donors have threatened to withhold funding and the Republican-led House of Representatives passed a resolution condemning their testimony.

In the first few days after the Oct. 7 Hamas attack and ensuing Israeli military retaliation in Gaza, most protests opposed Hamas and supported Israel, according to the Crowd Counting Consortium, a public service project that tracks nonviolent protest using news reports, social media posts and, as the name suggests, crowd estimates, among other sources. These rallies and vigils were held in tribute of the more than 1,200 people killed in the Hamas attack and the more than 200 taken hostage — the worst attack on Israel’s civilians in its history.

As the war intensified, that emphasis shifted, according to the CCC, with fewer demonstrations focused on Israel and a growing number in support of Palestinians.

According to the latest CCC update on Nov. 28, there have been more than 1,869 Palestinian solidarity protests in the U.S. since Oct. 7, involving — by its count — hundreds of thousands of people. “While nearly all of the early actions were demonstrations, rallies, marches, or protests on public sidewalks and streets, we’ve also seen a significant increase since mid-October of acts of civil disobedience and other deliberately disruptive actions,” Jay Ulfelder, a research director at Harvard’s Nonviolent Action Lab, wrote on the CCC blog Counting Crowds.

Demands for a cease-fire in the fighting over Gaza have become a rallying cry at the protests, as have as accusations of genocide against the Palestinian people and anger at the U.S. and President Joe Biden for their support of Israel, according to CCC’s tracking.

Protests can be important to understanding shifts in public opinion, or how willing members of the public are to mobilize for a cause. In this case, these U.S. protests come as Congress deliberates over $14 billion in funding to Israel, including for military uses, in addition to the $3.8 billion in U.S. aid the country already receives annually.

Though larger than past Palestinian solidarity protests, they still do not necessarily reflect the views of most Americans on Israel. According to a PBS NewsHour/Marist poll conducted Nov. 6 to Nov. 9, most Americans, about six in 10, said they sympathize with Israel, compared to three in 10 who are sympathetic toward Palestinians. At the same time, 38 percent of U.S. adults said Israel’s military response to Hamas has been “too much” — a 12 percentage point jump since October.

That was particularly true of Gen Z and millennial voters in the poll, 48 percent of whom said the military response was too much.

“I think the big story here is that there’s been a rupture between liberals and progressives,” New York Times columnist David Brooks told the PBS NewsHour’s Amna Nawaz on Nov. 17.

“It’s not only on the Middle East. On a bunch of other issues, you’re seeing this beginning — this rupture between progressives, who tend to be younger, and liberals, who tend to be older,” he added.

WATCH: Gaza civilians caught in crossfire face new threat with spread of deadly diseases

Gen Z and millennials are more Democratic than older generations, said Stephanie Calvano, director for data science and technology for the Marist Poll, but young people have increasingly shared this sentiment in recent weeks. At the same time, there is more willingness to protest against Israel’s bombardment of Gaza than there has been in the past, said Corey Robin, a political scientist at Brooklyn College.

“I would say that, until recently, pro-Palestine protests have definitely been confined to college campuses and Arab and Muslim communities. Most leftists I know, unless they were Jewish or Arab, tended to shy away from the issue, feeling like it was either too complicated or too controversial to take a public stand on. All that has changed,” Robin said.

Protesters demanding a ceasefire and an end to U.S. support for Israel’s attack on Gaza block morning traffic on the 110 Freeway, in Los Angeles, California, Dec. 13, 2023. Photo by David Swanson/REUTERS

The Palestinian solidarity protests have not been supported publicly by the vast majority of politicians, including from the Democratic Party, the CCC noted — writing that elected officials had only appeared at about 1 percent of Palestinian protests. By contrast, the March for Israel on Nov. 17 drew politicians from both parties, including top Congressional Democrats such as Senate Majority Leader Chuck Schumer and House Minority Leader Rep. Hakeem Jeffries, both of New York, along with Republicans like House Speaker Rep. Mike Johnson of Louisiana and Sen. Joni Ernst of Iowa. The CCC said that about one in four pro-Israel demonstrations were attended by an elected official. The protests are unlikely to influence politicians in the short-term, Robin said. But there may be longer term legacies.

“The thing that’s interesting about these younger voters, this constituency on the left, is they do not seem to be evanescent, that just sort of emerges for one thing and goes away and doesn’t come back. They seem to be progressively getting stronger and more organized and more institutional in figuring out how to leverage power,” Robin said.

How protests over this war compare to those in the past

While protests over the Israel-Hamas war have grown, they are still dwarfed by 2020’s Black Lives Matter protests, the 2017 Women’s March, and the last major anti-war protest in the U.S. against the invasion of Iraq, which on a single day in 2003 turned out several hundred thousand protesters in New York, Los Angeles and San Francisco alone. Those protests, however, built up over months and years of mobilization.

“Not remotely comparable,” said David S. Meyer, a professor of sociology and political science at the University of California, Irvine. He noted that anti-war protests are usually largest in the countries that are participants. “People were trying to restrain their own governments.”

If the Palestinian solidarity demonstrations have seemed “relatively modest” so far, University of Notre Dame professor David Cortright said that it also took time for the Iraq War “protests to emerge on a large scale in the U.S.”

Cortright, a peace activist and author of “A Peaceful Superpower: Lessons from the World’s Largest Antiwar Movement,” said that the resistance to the Iraq War built up as the nation recovered from the shock of the 9/11 attacks and as President George W. Bush’s administration made its case for war.

“The [early] protests were not huge,” Cortright said, “but a huge trigger was that people realized that Bush was actually going to do this.”

Cortright said the reaction time is sped up in the case of Israel, Hamas and Gaza. He added that conditions in which today’s protests exist are different than they were during the Vietnam War. Hamas is a stronger presence in the current conflict’s politics than the Vietcong were in Vietnam, for instance. With social media, more people are seeing dramatic images of the violence caused by Israel’s strikes. “I expect the protests to grow as the images continue,” Cortright said.

At the same time, social media can be a hurdle to broadening these types of social movements. Images or statements that come out of protests and travel across platforms can push the message beyond its original context, statements that might have been on the fringe of a protest become emblematic of the demonstration.

“At every protest you have someone making an extreme statement,” Cortright said. “What’s different is, social media can elevate these statements.”

Palestinian solidarity protests are not new in the United States, but they have been relatively small. Meyer said this is in contrast to other countries in Europe, where “Palestinian independence activists have been more successful at making in-roads.”

During an outbreak of violence between Israel and Hamas in May 2021, Ufelder said that a wave of pro-Palestinian protests in the U.S. began to expand to include the support of Indigenous activists, labor groups and organizations such as Black Lives Matter. This round of protests have drawn an even wider coalition.

Ufleder said this cause has started to pull in a wider swath of people from across the political spectrum — more centrist supporters along with the more liberal people and groups who have already shown support for Palestine, he said.

A similar shift was seen in 2020, when the protests over George Floyd’s murder broadened the group mobilizing around police brutality against Black people, Ufleder said.

Lauren Burgas and Jenna Bonarigu caravaned from Youngstown, Ohio, to participate in the Free Palestine march in Washington, D.C., in early November. They held homemade placards that called for a cease-fire and compared Israel’s actions in Gaza to the subjugation of Native Americans. “Colonizers are the real terrorists, this is native land,” it reads.

Burgas, a college student, said she got involved in the issue while she was dating a Palestinian man.

She said she began doing her own research, and while the relationship didn’t last, her interest in activism remained. She attended her first protest last year after the killing of Palestinian American journalist Shireen Abu Akleh.

“In the past, there wasn’t really an influx or like a huge crowd gathering for Palestinian protest and I think that we see this turning point in our generation,” Burgas said.

Bonarigu began protesting for women’s issues during college, and has since participated in demonstrations for Black Lives Matter, Native American issues and now Palestinian solidarity, all of which are connected in her view by power dynamics of who is in charge.

“It’s the imperialists. It’s all the people that are running the country for millions of people that think humanely and morally,” Bonarigu said.

Demonstrators march in support of Palestinians in Gaza, amid the ongoing conflict between Israel and Hamas, in Washington, D.C., Nov. 4, 2023. Photo by Elizabeth Frantz/REUTERS

Some Palestinian solidarity protests have featured speakers who celebrated the violence perpetrated by Hamas, used violent imagery or, in some cases, made antisemitic statements. At a Times Square rally in the days immediately after the attack, one protester was photographed flaunting a swastika on his phone in front of pro-Israel counterprotesters. Another was a speaker who mocked the deaths of people who were attending a dance festival in the desert when Hamas attacked.

But generalizing that all of the protests are anti-Israeli or anti-Jewish is “a cheap shot,” Cortright said. “One can demonstrate against a violent attack against civilians by Israel while also condemning Hamas. Movements will have trouble getting broader support if they’re not able to articulate, ‘We are patriotic Americans, we agree to counter terrorism, but war is the wrong way to do it.’”

Cortright, who began his career in activism against the Vietnam War while he was still an active duty member of the military, said protests of that era also dealt with images and controversy, including the carrying of the National Liberation Front of South Vietnam, whose armed wing was the Vietcong.

“But it wasn’t enough to discredit the overall movement. It was a tiny faction in the overall movement,” Cortright said.

Deeper political effects

Some Democratic state and local leaders have criticized the pro-Palestinian protests. In San Francisco, District Attorney Brooke Jenkins referred to one as a “pro-Hamas rally” in a post on X, after vandals wrote “Death 2 Israel” in graffiti on a downtown building. She later deleted her post after outcry from the local Arab American and Muslim community. In New York City, Gov. Kathy Hochul and Mayor Eric Adams condemned the protest held in Times Square as antisemitic.

Robin said Democratic politicians have attempted to “create a unity” around support for Israel but “the opposition and discontent is just that much greater” than in the past.

“Mainstream politicians in the Democratic party are kind of nervous and they don’t have the certainty they once possessed [about Israel]. It’s a lot more mixed,” Robin said. “There’s no doubt that there’s a rising constituency who are electorally active on the left and are in key battleground states.”

According to the PBS NewsHour/Marist poll, while 79 percent of Democrats approve of the job Biden is doing as president in general, that number drops to 60 percent when asked about his role in the war between Israel and Hamas. Recent polls have raised the possibility that Biden’s stance on Israel could cost him voters important to his 2020 victory, in particular Arab American voters in Michigan and young people.

His support of Israel as it lays siege to Gaza is costing him support among Arab Americans, an important part of his victory in Michigan – a swing state that had previously been won in 2016 by Donald Trump.

The discontent has not been limited to Democratic politicians – disagreements within left-wing organizations have also been played out in public. A member of the Democratic Socialists of America for 40 years, and a former member of the radical Students for a Democratic Society, announced he was leaving the organization in protest of what he described as its “politically and morally bankrupt response” to the Hamas attack in Israel. Others have defended the organization’s response and vowed to continue solidarity with Palestinians.

“I think Israel has always created conflict on the American left. I think people who are very tuned in to what’s going on now are very divided,” Meyer said.

“I think support for the Palestinians has grown, maybe faster than I anticipated,” Meyer added.

Meyer said the views of Americans may also be influenced by antipathy to Israel’s Prime Minister Benjamin Netanyahu, some members of his government and the likelihood that they’ll control Gaza after the dust settles.

“Netanyahu has announced that Israel may have to run Gaza for the foreseeable future, and rightwing members of his government have announced plans that sure sound like ethnic cleansing,” Meyer said. “Many Americans who want to support Israel don’t want to support all this government does.”

Cortright said protests often struggle to appeal to and gain support among the broader public. But on this war, protests coupled with broader shifts in public sentiment seem to be making a difference.

“The administration has been moving slowly and cautiously for political reasons, but they are edging in the direction of favoring a cessation of hostilities, even if they don’t use the word cease-fire,” he said.