This combo photo shows US President Joe Biden (left) in Salt Lake City on Aug 10, 2023, and former US president Donald Trump speaking in Bedminster on June 13 2023. (PHOTO / AP)

DEARBORN, Michigan - US President Joe Biden easily won the Democratic presidential primary in Michigan on Tuesday, Edison Research projected, but a protest vote by Democrats angry over his support for Israel’s war against Hamas in Gaza was growing as returns were counted.

Donald Trump won the state's Republican presidential primary by a large margin, Edison Research projected, strengthening his grip on the party’s White House nomination as Nikki Haley, his last remaining rival, came in a distant second.

Although Biden and Republican former President Trump had been expected to easily win their separate party primaries, the vote count for both was being closely watched for signs of wavering support.

In Michigan, home to a large Arab American constituency, Democratic voters had been urged to mark their primary ballots as "uncommitted" on Tuesday in protest at Biden's Gaza policy.

With 16 percent of the estimated Democratic vote counted, Biden had 80 percent support, with "uncommitted" getting 15 percent, and with 17 percent of the estimated Republican vote counted, Trump had 66 percent support to Haley's 29 percent, according to Edison Research

Early returns showed the number of "uncommitted" voters had exceeded 24,500 after 16 percent of Democratic ballots were counted. That was more than double the 10,000 target for uncommitted voters that protest organizers had been hoping for.

Many in Michigan's Arab American community who backed Biden in 2020 are angry, along with some progressive Democrats, over Biden's support for Israel's offensive in Hamas-ruled Gaza where tens of thousands of Palestinians have been killed.

"There's a lot of folks that are voting uncommitted who I think were not directly associated with the Arab American community," said Michigan pollster Bernie Porn. He said it remained to be seen how big of an issue the Middle East would be for Biden in November when the situation could look different.

ALSO READ: Republican Party leader McDaniel to step down after Trump pressure

Early returns showed Biden and Trump with solid overall leads. With 16 percent of the estimated Democratic vote counted, Biden had 80 percent support, with "uncommitted" getting 15 percent, and with 17 percent of the estimated Republican vote counted, Trump had 66 percent support to Haley's 29 percent, according to Edison Research.

Michigan routinely offers an “uncommitted” option as a way of questioning whether a named candidate has the support of the party’s base. It could not be determined how many of those votes were protesting Biden's Gaza policy.

Michigan is expected to play a decisive role in the head-to-head Nov 5 US presidential election, a likely rematch between Biden and Trump.

It is a battleground state that could swing toward either party. Biden beat Trump in Michigan by just 2.8 percentage points in the 2020 election.

US Republican presidential hopeful and former UN ambassador Nikki Haley speaks at a rally in Troy, Michigan, on Feb 25, 2024.  (PHOTO / AFP)

Nikki Haley to carry on 

Michigan turnout for former UN Ambassador Haley, who won nearly 40 percent of Republican votes in her home state of South Carolina on Saturday, was also being scrutinized for signs of vulnerability for Trump among moderates, whose support he would need in a general election.

Despite having lost to Trump in every primary race, Haley has performed well with moderate voters, although she has no clear path to the nomination.

On Tuesday, shortly before Trump was projected the winner in Michigan, Haley vowed to carry on.

"We've only seen a handful of states vote," Haley told CNN. "We're taking this one state one day at a time."

ALSO READ:Trump projected to win South Carolina Republican primary

Late on Monday, Biden said Israel had agreed to halt military activities in Gaza for the Muslim holy month of Ramadan expected to begin on the evening of March 10, as Hamas studied a draft for a truce that includes a prisoner-hostage exchange.

It should have happened sooner, said Michael Bristol, 21, a student at Wayne State University who said he cast an uncommitted vote.

Engage Action and Listen to Michigan said before the vote they were aiming for 10 percent of Michigan’s Democratic primary voters to mark their ballots uncommitted, a symbolically significant 10,000 votes – about equal to Democrat Hillary Clinton's loss in Michigan to Trump in the 2016 presidential election.

Democrats, overall, support Biden's handling of the Israel-Hamas conflict by 61 percent, February polling by Harvard-Harris shows.

Michigan Governor Gretchen Whitmer and other Democrats have warned that if Democratic voters abandon Biden, they could hand the swing state and the country back to Trump in November. Biden defeated Trump in the 2020 election.

A senior Biden campaign official said: "We're taking this seriously. The president himself has said repeatedly that he hears these demonstrators and that he thinks that their cause is important."

On Feb 1, Biden won a strong pledge of support from union autoworkers, a Michigan voting bloc no less crucial to his reelection bid. The state is home to nearly 20 percent of all US auto production, more than any state in the country.

Michigan's Republican Party, beset by internal turmoil, will allocate some delegates to the party's July convention based on Tuesday's primary results.

Rival factions are holding dueling party meetings on Saturday that will award the bulk of the delegates. It was unclear, however, which results will be official, although Trump was expected to handily win both sets of Saturday's votes.