A group of Palestinian rights advocates interrupted former Secretary of State John Kerry while campaigning for Joe Biden in Sioux City, Iowa on Tuesday. The activists held signs with the words “Palestinians should be free” while chanting “End Israeli injustice,” momentarily drowning out Kerry’s pitch for Biden’s presidential run.

Kerry seemed perplexed at the protest, and tried to engage one-on-one with the demonstrators. But the organizers were more interested in getting their message out, and soon after the disruption, left the event.

“Under Kerry and Biden, we saw a sharp increase of military funding to Israel, which is mired in human rights violations,” said Moe Elsherbiny, an Egyptian-Palestinian student at American University in Washington, D.C. who protested at the Biden event. “It felt liberating to take it directly to [oppressors]of Palestinian human rights, Kerry and Biden. We went to the belly of the beast.”

The protest was the first in a week-long swing of events planned across the state by Jewish Voice for Peace (JVP) Action, as the race to win the Iowa caucuses, the first Democratic primary contest, intensifies. Voters in Iowa will caucus on Feb. 3.

The protesters’ goal? Follow all the presidential candidates campaigning in the first primary state, amplify the call for Palestinian freedom, and demand that the Democratic candidates for president commit to ending U.S. military aid to Israel.

Fourteen JVP Action activists are currently in Iowa. They plan on educating Democratic primary voters on the crisis in Israel-Palestine while also challenging Democratic presidential candidates on their positions on Israel.

“Jewish, queer, Black, Muslim, Palestinian activists — they’re all going to be there with one unified call: 2020 is the year for Palestinian freedom and we have to stop funding Israeli injustices now so that Palestinians can be free,” said Beth Miller, government affairs manager for JVP Action.

The “Palestinian Freedom 2020” bus, organized by the electoral campaign arm of Palestine solidarity group Jewish Voice for Peace, is the latest instance of Palestinian rights advocates hitting the presidential campaign trail to insert Palestinian rights into the 2020 discussion. IfNotNow, the Jewish anti-occupation group, pressed numerous presidential candidates on the campaign trail over the summer, asking them what they plan to do about Israel’s military occupation of the West Bank and East Jerusalem, and the blockade of Gaza.

The debate over U.S.-Israel relations has since moved to prime-time. In November, Bernie Sanders, who is battling with Biden for front-runner status, brought up Israel-Palestine unprompted at a Democratic debate and said: “We must treat the Palestinians with the dignity they deserve.”

In December, debate moderators asked all the candidates whether they would limit U.S. aid over Israel’s building of settlements. Sanders responded by calling Israeli Prime Minister Benjamin Netanyahu a “racist” and said U.S. policy should be “pro-Palestinian” during the nationally-televised event. Biden, meanwhile, said Netanyahu’s conduct has been “outrageous” and that “we have to put pressure” on Israel, but “not withdraw physical aid from them in terms of their security.”

Now, JVP Action is trying to move the debate even further to the left. The organizers hope to get candidates to respond to their demand that the U.S. not only condition military aid to Israel — as Sanders has said he would as president — but end it completely.

“It’s often felt like there’s no hope for change. But this election cycle we’re seeing Palestinian rights finally becoming part of the progressive conversation and agenda in an unprecedented way,” said Miller.

Biden is an obvious target for JVP Action. As vice president under Barack Obama, Biden said Israel should stop constructing settlements. When the Netanyahu government continued to build on occupied Palestinian land, the Obama administration did not impose consequences on Israel.

In 2016, Biden helped negotiate the single-largest U.S. military aid package to Israel: a 10-year commitment to give the Jewish state $38 billion, with no strings attached on how these funds can be used. On the campaign trail, Biden said it would be “outrageous” to condition U.S. military aid to Israel.

But Biden is not the only candidate JVP Action’s “Palestinian Freedom” bus has followed. On Thursday, JVP activists questioned another hawkish presidential candidate, Senator Cory Booker, about U.S. support for Israel’s military detention of Palestinian children. JVP Action said they were disappointed that, in response, Booker “pivoted to Hezbollah & Hamas rather than children’s rights.”

Activists on the bus told +972 Magazine they’re aiming to get firm commitments from Senators Elizabeth Warren and Sanders to halt all U.S. aid to Israel — a demand that even the most progressive contenders are unlikely to echo. Warren has sharply criticized Netanyahu on the campaign trail, and has said the U.S. should pressure Israel to move toward a two-state solution, though Sanders has spoken about the issue with more detail and clarity than the Massachusetts senator.

To push Warren and Sanders to go even further than they have, the activists plan to question Warren and Sanders on the campaign trail as well, though likely in a different tone than the disruptive chants they used while interrupting Biden’s event.

“We have candidates like Joe Biden that flat out disregard the humanity of Palestinians. We also have candidates like Bernie who is showing promise on the need for Palestinian freedom,” said Eve Glazier, a Jewish student on the JVP bus who attends Barnard College in New York City.

But, Glazier added, “none of the candidates are truly taking a strong enough stand. None of the candidates have committed to cutting funding for the Israeli military. We want to make sure the candidates who are showing more promise make those commitments.”