House Democrats' internal split over a vote to cut off U.S. aid to Israel has extended to leadership, with Minority Leader Hakeem Jeffries (D-N.Y.) and Minority Whip Katherine Clark (D-Mass.) planning to vote differently.Why it matters: Such a divergence between the caucus' top two leaders is exceedingly rare and underscores just how much anxiety this vote is giving some in the party.Many House Democrats have substantive misgivings but plan to vote for the measure anyway due to growing political pressure from the left. "There are going to be people within our own party trying to drag us over the coals," one House Democrat told Axios on the condition of anonymity to speak candidly about the political pressures undergirding their vote."So you don't get to a place of like, 'Okay ... it isn't good for us to vote for an amendment that is poorly drafted and has all kinds of unanticipated consequences,'" the lawmaker added.Driving the news: Clark said in a statement Wednesday morning that she will vote for an amendment to a State Department funding bill proposed by Rep. Thomas Massie (R-Ky.) to block any of the money from going to Israel."It is clear that the status quo is not tenable. We should not provide a blank check for military aid to any country that does not comply with U.S. law, interests, and values," the No. 2 House Democrat said.Clark said she "will be voting yes, not because I agree with the entirety of the amendment, or the GOP's cynical motivations for its consideration, but because I believe we must change course."State of play: Jeffries said Tuesday he planned to vote against the amendment but that his team would not be whipping it and that members were free to vote their consciences.He wrote in a letter to colleagues that while "a meaningful change in direction is needed" for the U.S.-Israel relationship, "there are more decisive ways to achieve the urgent change necessary when it comes to the far-right Netanyahu government."Members tell Axios the vote could split the 212-member caucus squarely down the middle, with estimates ranging from 100 to 150 votes in favor of the amendment.Between the lines: At issue for many Democrats is that the Massie amendment includes no carveout for non-military aid.The measure, Clark said in her statement, "blocks all foreign aid to Israel, including humanitarian funding from Palestinian refugees and civilians in Gaza."She added: "This is not an attempt to have a serious and necessary debate about offensive military aid to Israel. It's more stunts from Congressional Republicans who would rather score cheap political points than lead."The bottom line: For many Democrats, this is simply about avoiding anger from the left — and a potential primary challenge.The House Democrat who spoke anonymously said the expectation is that the grassroots will "absolutely" punish anyone who votes against the measure."Even if it doesn't make any sense, even if it's poorly drafted, even if there's no precedent for anything like this — you can't message that."