The depth of Democratic Party anger over U.S. President Joe Biden’s handling of the Gaza war has caught his campaign off guard and could depress support in November’s election, according to interviews with more than a dozen senior party and campaign officials and five dozen voters and activists.

The White House had expected Democratic unrest over Gaza to fade as Biden picked up his campaigning against presumptive Republican nominee and former U.S. President Donald Trump, the officials said.

Nine months before the election, the problem is worsening as Biden’s opposition to calling for a permanent cease-fire continues to stir anger in a coalition of voters that propelled his 2020 victory, from Black Americans to Muslim activists in must-win Michigan to young voters, according to the interviews.