US President Joe Biden cruised to an easy victory in Michigan’s presidential primary on Tuesday — but was bracing for a substantial rebuke from an Arab American-led protest over his handling of the war in Gaza.

There was little suspense over the outcome for both parties, with Biden almost unopposed in the Democratic nominating contest and Donald Trump declared the early victor in a two-part Republican vote that doesn’t even conclude until the weekend.

But after polling stations closed Tuesday evening, counties were initially reporting 16 percent of Democrats in the key battleground voting for “uncommitted” rather than Biden, part of a push to persuade the president to back off from his support of Israel.

That figure has been under two percent in the last two election cycles and 11 percent the last time a sitting Democratic president sought reelection — when Barack Obama won in 2012.

The mounting civilian death toll in the Israel-Hamas conflict has weakened Biden’s standing among Muslims and Arab Americans, a bloc crucial to his narrow 2020 victory in Michigan over Trump.

The midwestern state has the largest proportion of residents who identify as being of Middle Eastern or North African descent in the country, with most of the population concentrated around Detroit.

Activists in the key battleground had asked Democrats to vote “uncommitted” to censure the president over US military funding for Israel, and to push a call for an immediate ceasefire.