As the U.S. Congress gears up to vote on a supplemental spending package that includes $14.3 billion in aid for Israel, Democrats on the Hill have started questioning the long-standing bipartisan consensus in Washington to supply military aid to Tel Aviv with very few strings attached.

President Joe Biden and a large majority of Congress have thus far expressed full support for Israel’s military response to Hamas’s October 7 attack, but a short-term pause in the fighting has given some Democrats time to air concerns about how Israel is waging its war. Nearly a dozen senators met with Israeli officials in Washington on Monday to have what Sen. Tammy Duckworth (D-Ill.) called an “extremely frank” discussion about how the war is unfolding.

Democratic senators have remained tight-lipped about whether they support placing conditions on aid to Israel or how they will vote on the upcoming spending package, instead conveying general discomfort with Israel’s conduct during a war in which it has killed more than 15,000 Palestinians, most of them women and children, according to the government media office in Gaza. Senators have also expressed concern about escalating settler violence against Palestinians in the West Bank.

“We want the president to secure express assurances from the Netanyahu government regarding a plan to reduce the unacceptable level of civilian casualties, and we want the Netanyahu coalition to commit to full cooperation with our efforts to provide humanitarian assistance to civilians in Gaza,” said Sen. Chris Van Hollen (D-Md.). “The bottom line is we need those express assurances. How we achieve that is something that we are discussing right now.”

“I fully support Israel’s right to pursue those who ordered and carried out the attacks of October 7th. But Israel must not do so in a way that leads to massive civilian casualties and the large-scale destruction of civilian infrastructure in Gaza,” added Sen. Peter Welch (D-Vt.) in a statement. “This will only incite more enemies against Israel and the U.S.”

This growing discussion serves as more evidence that Washington’s support for Israel’s war is causing a split among Democrats in Congress. While Biden has helped broker a short-term pause to hostilities that is set to expire this week, other Democrats have demanded that the U.S. push for a more long-term ceasefire. In the nearly two months since the October 7 attacks, the number of Democrats who publicly support a ceasefire has slowly grown to 49 as of Wednesday. Public opinion polling has shown that a strong majority of Americans support a ceasefire in Gaza.

“Achieving a lasting ceasefire remains the most urgent priority for all sensible advocates and policymakers,” Erik Sperling, the executive director of Just Foreign Policy, tells RS. “But as efforts to secure a ceasefire continue, it is encouraging to see growing talk about conditioning aid to Israel, which was once unimaginable on Capitol Hill.”

Sen. Bernie Sanders (I-Vt.), who has been criticized by progressive advocates for stopping short of calling for a ceasefire, has been one of the few Senate Democrats to explicitly endorse making military aid subject to more conditions on the way it is used. “Currently, we provide $3.8 billion a year. President Biden has asked for $14.3 billion more on top of that sum and asked Congress to waive normal, already-limited oversight rules. The blank check approach must end,” Sanders wrote in a New York Times op-ed last week. “The United States must make clear that while we are friends of Israel, there are conditions to that friendship and that we cannot be complicit in actions that violate international law and our own sense of decency.”

Other Democrats have pushed back on this idea. “Any legislation that conditions security aid to our key democratic ally, Israel, is a nonstarter and will lose scores of votes," Rep. Josh Gottheimer (D-N.J.) said in a statement.

“I don’t think there’s a need for conditionality,” Senate Foreign Relations Committee Chair Ben Cardin (D-Md.) added on Monday. “The way the president has handled his conversations with the Israelis has produced tangible results, including the amount of humanitarian assistance and the strategy on the military side.”

Amid these debates, U.S. Senators were shown a film produced by the Israeli government showing footage of the Hamas attacks in October. The images left Senators in “tears and silence,” according to the Jewish Telegraphic Agency.

Biden has called the idea of conditioning aid a “worthwhile thought,” but administration officials has since said that it was “not something we’re currently pursuing,” according to Politico.

The Intercept reported on Tuesday that Sanders could force a vote on conditioning aid in the coming weeks.

Conversations in the Democratic caucus revolve around the Leahy law, which prohibits the U.S. from providing military aid to specific units where there is credible information that they have committed gross violations of human rights. As Josh Paul, a veteran State Department official who resigned in protest of the administration’s approach to the war, explained to RS last month, Israel is held to different standards than other countries when it comes to the application of the law.

“For most countries, we vet the units that are receiving the systems before they receive the assistance,” Paul said. “In the context of Israel, we provide the assistance, and then if certain allegations come to light of potential gross violations of human rights, we investigate those and decide if such things have actually happened.”

What these discussions in the Democratic conference mean for U.S. policy in the short-term remain unclear, especially as most in Congress continue to strongly support aid for Israel, but as the war likely continues, it will be a question that lawmakers may not be able to avoid.

“Irreversible trends in how voters see Israel's brutal actions means this focus will only increase going forward,” says Sperling. “In light of Israel's unprecedented toll on human life and also on U.S. global credibility, ending U.S. complicity in these cruel and illegal Israeli policies can't come soon enough.”

Senate Majority Leader Chuck Schumer, has said that the Senate will vote on the administration’s emergency supplemental request as soon as next week, but a possible attempt to condition support for Israel only adds another roadblock to a sprawling bill that will likely also spark debates over future aid for Ukraine and border security policies.