The Democrats lost the White House in 1968 amid anti-war protests. What will 2024 bring?

When student Lauren Brown first heard the commotion, including firecrackers, she assumed the sounds were coming from nearby frat houses. Then, at about four in the morning, she heard helicopters. Later, she awoke to news and footage of a violent attack by pro-Israeli protesters on an encampment set up to oppose the war in Gaza.

“It was hard to watch,” said Brown, 19, a freshman at the University of California, Los Angeles, whose dorm was near the encampment. “And I wondered where the police were. I saw posts from people talking about them being teargassed and maced and campus security was just watching.”

Related: Mass deportations, detention camps, troops on the street: Trump spells out migrant plan

Eventually, a large police contingent did arrive and forcibly cleared the sprawling encampment early on Thursday morning. Flash-bangs were launched to disperse crowds gathered outside and more than 200 people were arrested. Afterward, campus facility workers could be seen picking up flattened tents and pieces of spray-painted plywood, and throwing them into grey dumpsters.

Similar scenes of tumult have played out this week at about 40 universities and colleges in America, resulting in clashes with police, mass arrests and a directive from Joe Biden to restore order. The unrest has unfolded from coast to coast on a scale not seen since the Vietnam war protests of the 1960s and 1970s.

The president has cause for concern as the issue threatens his youth vote, divides his Democratic party and gives Donald Trump’s Republicans an opening to push allegations of antisemitism and depict Biden’s America as spiralling out of control.

There are inescapable parallels with 1968, a tumultuous year of assassinations and anti-war demonstrations that led to chaos at the Democratic National Convention in Chicago. Democrats lost the White House to Republican “law and order” candidate Richard Nixon.

Now, there are fears that history will repeat itself as anti-war protests again convulse university campuses, and the Democratic National Convention again heads to Chicago. Biden faces Republican “law and order” candidate Donald Trump in November’s presidential election.

Bernie Sanders, an independent US senator from Vermont, told CNN this week: “I am thinking back and other people are making this reference that this may be Biden’s Vietnam.”

Drawing parallels with President Lyndon Johnson, whose considerable domestic achievements were overshadowed by the Vietnam war and who did not seek reelection in 1968, Sanders added: “I worry very much that President Biden is putting himself in a position where he has alienated not just young people but a lot of the Democratic base, in terms of his views on Israel and this war.”

The Gaza war started when Hamas militants attacked Israel on 7 October last year, killing about 1,200 people, mostly civilians, and taking about 240 hostage. Israel’s retaliatory offensive has killed more than 34,600 people in Gaza, mostly women and children.

The ferocity of that response, and America’s “ironclad” support for Israel, ignited protests by students at Columbia University in New York that rapidly spread to other campuses across the country. Students built encampments in solidarity with Gaza, demanding a ceasefire and that universities divest from Israel. The demonstrations have been mostly peaceful, although some protesters have been caught on camera making antisemitic remarks and violent threats.

University administrators, who have tried to balance the right to protest and complaints of violence and hate speech, have increasingly called on police to clear out the demonstrators before year-end exams and graduation ceremonies. More than 2,300 arrests have been made in the past two weeks, some during violent confrontations with police, giving rise to accusations of use of excessive force.

Biden, who has faced pressure from all political sides over the conflict in Gaza, attempted to thread the needle on Thursday, saying: “We are not an authoritarian nation where we silence people or squash dissent. But neither are we a lawless country. We’re a civil society, and order must prevail.”

The president faces opposition in his own party for his strong support for Israel’s military offensive. Hundreds of thousands of people registered versions of “uncommitted” protest votes against him in the Democratic presidential primary.

Yaya Anantanang, a student organiser at George Washington University in Washington, told the Politico website: “My message is that we do not support Biden. We do not capitulate to the liberal electoral politics, because, quite frankly, the liberation of Palestinians will not come through a Democratic president but by organizing and ensuring that there is full divestment within all of these institutions.”

Such views ring alarm bells for those who fear that even a small dip in support from Biden’s coalition could make all the difference in a tight election.

Kerry Kennedy, the daughter of Robert F Kennedy, who was gunned down while running for president in 1968, urged the protesters to support Biden despite their misgivings. “We need their votes now,” she said. “They might not love Joe Biden’s policies but the choice is not between Joe Biden and their ideal. The choice is between Joe Biden and Donald Trump, who’s going to institute the Muslim ban on day one.”

Republicans, meanwhile, are seeking to exploit the unrest for political gain. They have accused Biden of being soft on what they say is antisemitic sentiment among the protesters and Democrats of indulging “wokeness” in America’s education system.

Chris Sununu, the Republican governor of New Hampshire, said: “The crisis you’re seeing on college campuses is a result of the colleges themselves not having and pushing the right education, the right discussion in the classrooms, in the right way. They play this woke game where they don’t want to touch an issue.

“They create a vacuum of information. The students get bad information and propaganda. They’re effectively being used by terrorist organisations overseas to push an anti-American, anti-Israeli message, which is just awful. It’s not a difference of opinion. It’s complete misinformation.”

Images of disarray on campus have played endlessly on Fox News and in other rightwing media, feeding a narrative of instability and lawlessness under Biden while conveniently sucking political oxygen away from Trump’s own negatives.

On Tuesday, for example, the Republican nominee was in court for his hush-money trial; Time magazine published an interview in which Trump set out an extremist vision of an imperial presidency; and Florida introduced a six-week abortion ban after Trump helped overturn Roe v Wade. But TV screens were dominated by the protests.

Ezra Levin, co-founder and co-executive director of the progressive movement Indivisible, said: “All of those stories – any individual one would have been possibly disqualifying for a presidential candidate in a previous election – received a fraction of the coverage of the protests against [the Israeli prime minister Benjamin] Netanyahu’s massacre of Gazans.

“That’s problematic for those of us who want to see Joe Biden re-elected and want to see Democrats win because every day that we spend talking about this immoral war that US tax dollars are supporting is a day we’re not talking about the dangerous, creeping fascism presented by the Republican party.”

Still, Democrats hope that, with the academic year soon drawing to a close, students will head home for the summer and the energy will disperse. Donna Brazile, a former interim chair of the Democratic National Committee, doubts that the issue will be decisive in November.

“We’re going to have an October surprise every month, and we cannot predict which of the many surprises will actually drive the election.” she said. “A month ago, it was abortion was going drive the election. Now it’s the campus protesters. Next month it’ll be something else.”

Brazile also defended the students’ right to protest as past generations have against the Vietnam war, South African apartheid, the Iraq war and, during the most recent election campaign, police brutality. “I’ve been on several college campuses and the majority of them are quite peaceful,” she said.

“These are students who are using their first amendment right to advocate for change in the Middle East, and everyone has to be clear that there are rules. Just a handful have gotten out of control because if you violate the rules or break the law, you you have no right to do that. That is forbidden.”