For decades, the U.S. electoral politics of the Israeli-Palestinian conflict have been defined by a very simple fact: Voters almost never changed their ballots because of it.

As Israel’s devastating offensive in the Gaza Strip enters its fourth month, an estimated 22,000 Palestinians have been killed and the rest of the 2.3 million people in Gaza are suffering from mass starvation and continued bombardment after a shock Oct. 7 attack by Gaza-based militants that killed 1,200 Israelis. The question for political operatives in the United States is whether the current crisis in the region will have an unprecedented effect on American voters, particularly Democrats, given the near-universal agreement on full-scale backing of Israel among Republican politicians.

The answer could determine how close a series of key Democratic Senate primaries will be, whether progressive Democrats can retain the ground they’ve gained since 2016 and potentially whether President Joe Biden can triumph in an important swing state.

“Traditionally, Israel itself has not been a very salient issue in campaigns directly,” said Mark Mellman, a Democratic pollster who leads the Democratic Majority for Israel, a super PAC aiming to maintain a hard-line pro-Israel position in the party. Mellman noted, though, that it has long motivated people on both sides of the divide to get involved as volunteers and donors. “Is there going to be a big back and forth on this between us and other groups or between candidates? That remains to be seen.”

Political strategists on both sides of the issue within the Democratic Party are still puzzling over the new playing field, unsure if they can effectively use a candidates’ position on a cease-fire or their ties to hard-line pro-Israel groups, such as the American-Israel Public Affairs Committee (AIPAC), as a way to actually move voters.

“This is one of the first times Israel and Palestine have received wall-to-wall coverage in the months leading up to the primaries,” said Waleed Shahid, a progressive activist and the former communications director for the left-wing group Justice Democrats, which backed many of the highest-profile House members resisting the party’s history of largely unquestioned support for Israel. “This issue is going to be more salient. It’s going to be an area where candidates try to draw contrast.”

Polling over the course of the conflict has shown the public remains broadly supportive of Israel, even as sympathy for Palestinians has grown, especially among Democrats. At the same time, both Democrats and independent voters have grown skeptical of Israel’s devastating offensive in Gaza and become more supportive of a cease-fire between Israel and Hamas, the dominant armed group in Gaza and the top target of Israel’s military operation there. By maintaining near-total support for Israel’s campaign as it has become controversial, the Biden administration has become increasingly isolated; most countries globally and a notable chunk of Democratic politicians domestically now endorse a cease-fire.

Recent polling exclusively obtained by HuffPost confirms the trend: A December survey from ReThink Media, paid for by the Win Without War Education Fund and Oxfam America, found Americans who did not already have strong opinions on the conflict ― in other words, those who could be persuaded ― were more likely to vote for a candidate who supported a cease-fire than one who didn’t. Three-tenths of those surveyed said they would be more likely to vote for a candidate who supported a cease-fire, while 14% said they would be less likely.

The poll also reported that 40% of persuadable voters said it would have no effect on their votes.

“What the polling showed is that the continued conventional D.C. wisdom that pushing for a cease-fire is bad politics isn’t just wrong, it’s 180 degrees off,” argued Stephen Miles, the president of Win Without War, a well-connected left-leaning advocacy group. “It really shouldn’t be surprising given all the public polling we’ve seen, but people are inclined to support politicians who support policies they want. In this case, what’s good policy is also good politics.”

The basic dispute is not about support for Israel. Nearly all cease-fire supporters are staunch allies of the state, as is the Democratic Party overall. Rather, it’s about to what extent the U.S. relationship with Israel should include pressure to abide by international and American norms over conduct in war ― and whether being “pro-Israel” entails unchecked backing of right-wing Israeli Prime Minister Benjamin Netanyahu.

More than 60 Democrats in Congress have called for a cease-fire so far. One of them, Rep. Ro Khanna (D-Calif.), told HuffPost he hopes to persuade more colleagues to join the call in the coming days, describing three arguments he is making to them: appealing to their consciences, given the suffering of Gazans; saying the position may eventually become a no-brainer, given younger voters’ tendency to be more empathetic toward the Palestinians; and warning that Israel’s current military plan risks creating “an endless war.”

Taking the position remains “politically challenging,” Khanna acknowledged. Still, he pledged that some in the party would support Democrats if they are targeted by more aggressive pro-Israel groups, saying he plans to do so and the Congressional Progressive Caucus would as well.

The status quo made some sense. Voters with the most explicit ties to the conflict ― Jewish Americans and Muslim Americans ― combined make up only about 3% of the U.S. population, and large swaths of the country have few economic and emotional ties to a conflict 6,000 miles away. Though American public opinion has long been broadly pro-Israel, voter support for the country generally came second to issues such as the economy, civil rights, education and health care or broader concerns about terrorism and national security.

That meant that even as the establishment side of the divide has greatly stepped up its spending in recent years, pouring millions into groups like Democratic Majority for Israel (DMFI) and an AIPAC-linked super PAC called United Democracy Project, those groups have rarely directly aired ads about Israel policy, instead typically choosing to attack progressives on unrelated issues. They recently broke from this pattern to air ads against Rep. Rashida Tlaib (D-Mich.), the only Palestinian-American in Congress, on issues directly related to Israel and antisemitism.

Democrats are already preparing for tough challenges to lawmakers who have long been targeted by pro-Israel forces, including Reps. Ilhan Omar (D-Minn.), Summer Lee (D-Pa.) and Tlaib. They also know new targets may be at risk because of their cease-fire advocacy. Speaking on condition of anonymity to maintain professional relationships, a Democratic House member told HuffPost that Reps. Maxwell Frost (Fla.), Jamaal Bowman (N.Y.) and Greg Casar (Texas) are especially vulnerable.

“AIPAC is pragmatic in terms of who they could actually beat,” the lawmaker said.

A key factor in whether these progressives can actually fend off AIPAC-backed challengers is if progressives can successfully argue AIPAC is a barrier to resolving the Israeli-Palestinian conflict and use challengers’ ties to the group against them. Challengers to Omar, Bowman and Rep. Cori Bush (D-Mo.) are expected to receive heavy backing from pro-Israel groups.

“The challenge for progressives is can they inform the average voter of who AIPAC really is, in the same way 20 or 30 years ago the average Democrat did not really know what the National Rifle Association was,” Shahid said.

One advantage pro-Israel groups have: Younger voters are far more skeptical of Israel than older voters, but older Americans are far more likely to turn out to vote in primaries.

“Are young people, who are overwhelmingly concerned with the economy, going to turn out in droves for anti-Israel candidates because they’re anti-Israel?” Mellman asked. “I have every reason to doubt that. That’d be a radical change in behavior.”

The most striking example of how the issue is playing in Democratic politics may actually be in California’s Senate race, where the three Democratic candidates competing in the all-party March 5 primary started with distinctly different positions on the issue: Rep. Barbara Lee immediately called for a cease-fire, Rep. Adam Schiff stuck to the standard pro-Israel line and Rep. Katie Porter tried to find a middle ground, criticizing Israel’s right-wing government without calling for a cease-fire.

Shortly before Christmas, that shifted, with Porter endorsing a “lasting bilateral cease-fire” in the fighting between Israel and Hamas. The shift came as polls showed Lee, who had long trailed both Porter and Schiff, beginning to catch up with the second-place candidate. Porter’s team is now betting their position is more broadly acceptable to the electorate than either Lee’s or Schiff’s.

However, there’s been little indication that Schiff, who now has $35 million cash on hand ― has suffered for his firmer pro-Israel stance, and it’s possible he may be the only Democrat to advance in California’s all-party primary system, essentially guaranteeing him the seat in November. It’s also difficult to determine how much of a role Lee’s support for a cease-fire played in her rise in the polls.

“It highlights the through-line of her positions, dating back to the days after 9/11 and the [authorization for use of military force], as a national leader for peace,” said Anna Bahr, a spokesperson for Lee, referring to the congresswoman’s famous position as the lone no vote on the invasion of Afghanistan in 2001.

The issue has also begun to crop up in two other major Democratic Senate primaries: Rep. David Trone (D-Md.), who is running against Prince George’s County Executive Angela Alsobrooks, endorsed a cease-fire earlier this week after spending most of his career as a close ally of AIPAC. In Michigan, actor Hill Harper has played up his support for a cease-fire in his long-shot bid against Rep. Elissa Slotkin.

How the issue of Israel plays out in these primaries will serve as a preview for how much it could affect President Joe Biden, who has seen his approval rating with young voters and Muslim and Arab voters slip significantly since the Hamas attack and Israel’s bombardment. Leading Democrats have hoped the issue would decline in importance before November, expecting it to start disappearing from the news cycle.

At the moment, the issue continues to dog the president. Cease-fire supporters interrupted his speech on Monday in South Carolina, and anonymous groups of both White House and campaign staffers have signed letters supporting a cease-fire.

“I understand the passion, and I’ve been quietly working ... with the Israeli government to reduce ― significantly get out of Gaza,” Biden said as the protesters were led out on Monday.

The issue is central in swing state Michigan, which sports one of the largest Arab and Muslim populations in the country and where many community leaders have already sworn off voting for Biden.

“The same way that they’re being silent right now in the face of injustices, we’re going to be silent in November 2024,” Adam Abusalah, an organizer in the state’s heavily Arab American city of Dearborn, told CBS last month.

Biden was worried enough about his standing in the state to announce on Wednesday plans to travel there in the coming weeks.

For the voters who could make the issue a serious concern for Biden, two aspects of the president’s approach since Oct. 7 are key: the U.S. government’s overall policy of overwhelmingly supporting Israel while partially encouraging restraint and humanitarian aid for Gaza; and Biden’s personal reaction to the crisis.

Muslim American organizations have organized scores of protests urging Biden to seek an Israel-Hamas cease-fire. And their community has been especially disturbed by the impression that he is not as concerned with the suffering of Palestinian civilians as that of Israelis.

In October, Biden publicly suggested that authorities in Gaza were lying about the staggering death toll there. The comment sharply contrasted with his long-time reputation as a politician particularly focused on empathizing with those in pain ― and with the assessment by U.S. officials and outside experts that authorities are generally the most accurate source of information about conditions in the Palestinian enclave; HuffPost revealed that the State Department regularly cited Gazan figures internally with few caveats.

The president privately apologized for his doubting remark to a group of Muslim American leaders the following day, according to The Washington Post, but he has not publicly addressed it since.

Americans with family members trapped in Gaza have also been blasting the Biden administration’s failure to help their loved ones leave the territory. U.S. officials have privately conceded that Israel is preventing some of those individuals from being placed on the exist list and have claimed they’ve been told to tell citizens it is safer for them to stay where they are than to try to leave, HuffPost reported in December.

“If you move in Arab American or Muslim American circles, as I do, support for Biden’s reelection is rapidly crumbling,” Mustafa Bayoumi, a U.S. columnist for The Guardian, wrote in an essay published Tuesday.