Just over 100,000 people in Michigan voted "uncommitted" in the US swing state's Democratic primary, provisional results showed Wednesday, after a protest movement urged voters to punish President Joe Biden over his support for Israel's war in Gaza.

Though Biden handily won the vote, the uncommitted ballots, representing 13 percent of votes cast Tuesday, sent a "clear and resounding message that we demand a permanent ceasefire now," Layla Elabed, an organizer of the Listen to Michigan campaign, told a press conference.

The midwestern state is home to a large number of Arab and Muslim Americans, previously firmly part of the Democratic fold that helped elect Biden in 2020.

Whether Biden could change tack -- and whether those who registered a protest vote in the primary will continue to do so in November -- could be key as the United States heads toward a likely rematch between Biden and former president Donald Trump.

Though the percentage of uncommitted votes was similar to that seen in 2012 during Democrat Barack Obama's reelection campaign, where it hit 11 percent, that year's uncommitted result only represented some 20,000 votes.

Joining in the pressure campaign against Biden were elected officials, with local mayors as well as Rashida Tlaib, the only Palestinian American representative in Congress, casting uncommitted ballots.

Previous victories in Michigan -- seen as crucial to winning the country as a whole -- have been narrow: Donald Trump won by about 10,000 votes in 2016; Biden won by some 150,000 in 2020.

"It is my hope, Mr. President, that you listen to us," said Abdullah Hammoud, the mayor of Dearborn, a Detroit suburb home to a large number of Arab Americans.

"That you choose democracy over tyranny. That you choose the people of America over (Israeli Prime Minister) Benjamin Netanyahu."

Asked about the risk of electing Trump in November, Hammoud said that was a question that should be posed to Biden.

"President Biden is the one seeking the highest office and he is the candidate who's facing off against Donald Trump," he said. "He has to earn the votes of the constituency that he's trying to serve."

In a statement Tuesday night after his victory was declared, Biden thanked "every Michigander who made their voice heard today."

It did not mention the protest vote.

"Quite frankly, his statement last night did not unite," said Abbas Alawieh, a Listen to Michigan spokesman, adding the president "ignored" the 100,000 uncommitted voters.

"This community here in Michigan needs him to change his policies before he comes back and asks for our votes."

White House spokeswoman Karine Jean-Pierre said Wednesday that "US policy is not going to change on this."

"We're going to continue to listen," Jean-Pierre told reporters, while pushing for "a temporary ceasefire."