Democratic lawmakers are publicly and privately cautioning that the sizable anti-Israel protest vote in Michigan's primary this week is a warning sign for their party going into the November elections.

Why it matters: It's an issue that has harshly divided Democrats in the aftermath of Hamas' brutal Oct. 7 attack on Israel.

• Lawmakers fear President Biden's support of Israel will be a problem — particularly for progressive voters — as long as the fighting rages on in Gaza.
• "A ceasefire would be [good] for a lot of reasons. The electoral effect obviously is not the principal reason, but it's important," one senior House Democrat told Axios.
• "It's tough," said another. "So many of my colleagues, my God, they have to be removed from these events by police. It's like, 'Wait I agreed with you!' "

Driving the news: More than 100,000 people voted "uncommitted" in Michigan's Democratic presidential primary on Wednesday, comprising more than 13% of the vote to Biden's 81%.

• The "uncommitted" vote was highest in areas with large Arab American populations, such as Dearborn.
• A pro-Palestinian movement cropped up in the months leading up to the vote urging an "uncommitted" vote to protest Biden's support for Israel.

Zoom out: Gripping scenes of human tragedy continue to emerge from Gaza — most recently a grisly incident Thursday in which dozens of Palestinians were killed in an incident around an aid convoy.

• Biden, after saying Monday his "hope" was that a temporary ceasefire would be brokered over the weekend, warned on Thursday that the episode likely will complicate those negotiations.

What they're saying: Progressives said the primary result should be a wakeup call for Biden. "It was definitely significant," said Rep. Jamie Raskin (D-Md.).

• Rep. Alexandria Ocasio-Cortez (D-N.Y.) called it a "very powerful statement ... about the path to victory for Democrats in November."
• "Our coalition from 2020 was fragile. ... I think it's going to be a challenge this time," said Progressive Caucus chair Pramila Jayapal (D-Wash.).
• Sen. Elizabeth Warren (D-Mass.) said the vote signals "we all need to be tougher on Netanyahu and Israel."

The other side: Staunch Biden allies and Israel supporters focused on the fact that the 13% "uncommitted" vote was roughly in line with what former President Obama saw in his uncontested Michigan primary in 2012.

• "This is not a story ... 'uncommitted' has gotten votes in the past," said Rep. Jared Moskowitz (D-Fla.).
• Rep. Hilary Scholten (D-Mich.) noted that Biden received about three times as many votes in Michigan as Obama got in 2012.
• "The number of supporters who came out for Joe Biden when they otherwise didn't have to, I think, sends a resounding message," she said.

Between the lines: A third House Democrat told Axios a ceasefire "would make our lives easier for sure," but said the Michigan results have been "overstated" and that Gaza won't be a "determinative" issue in November.

• "For sure it would be great to have out of the way. But I'm afraid Biden is making promises about a ceasefire that won't turn out to be true."
• "People understand the terrible nature of the conflict," Raskin said. "We have a famously compassionate president, and people want to see his compassion extends to everybody who is suffering over there."

Stephen Neukam contributed reporting.