Over 6,000 Georgia voters left their ballots blank in Georgia’s Democratic presidential primary, an organized effort to send a warning to President Joe Biden over his support of Israel’s war against Hamas.

The “Leave it Blank” effort, which amounted to about 2.2% of all Democratic ballots cast Tuesday, is the latest warning from primary voters that they could withhold their votes for Biden in the November election against Republican Donald Trump. It is unclear how many of the blank ballots came from protesters.

Georgia’s protest vote follows mobilizations in several other primaries, led by Michigan, where 13% of Democratic primary voters picked “uncommitted” instead of a candidate. Georgia doesn’t have an “uncommitted” option, but state law allows voters to turn in blank ballots.

“It’s important that we send the president a message that if he is expecting to win this state ... he needs to end the war in Israel and Gaza,” 34-year-old Devin Barrington-Ward, a former candidate for the Atlanta City Council, said after voting Tuesday. “Folks are going to be having real serious questions with themselves around what is the point of having this president if he’s going to have us in a protracted conflict in the Middle East.”

At least 6,446 Democratic voters left their ballots blank across Georgia, according to an analysis of election results and turnout by The Atlanta Journal-Constitution.

Some of the highest rates of blank Democratic ballots were found in metro Atlanta counties, including 8% in Forsyth County north of Atlanta, a conservative-leaning area with a growing number of liberal voters. Clinch County in South Georgia had the state’s biggest proportion of blank Democratic ballots, at 11% of 189 ballots cast.

The number of blank ballots exceeded expectations and showed the importance of the Israel-Hamas war to Democratic voters, said state Rep. Ruwa Romman, a Palestinian American Democrat from Duluth.

“People are very upset. They’re willing to take the time to give a warning because they recognize how big of a deal and how existential November’s election is going to be,” Romman said. “Folks are motivated on this issue, and they are saying if you stand with us, we will come out for you in droves.”

Organizers of the blank ballot movement said they want a cease-fire in the Gaza Strip, humanitarian aid and an end of providing U.S. weapons to Israel.

Biden has been working to negotiate a cease-fire while still supporting Israel, and he proposed a temporary pier on the coast of Gaza to boost the flow of aid.

“There is no way President Biden can expect to win Georgia if the thousands of young voters and people of color who supported him and mobilized for him in 2020, most of whom oppose his Gaza policy, decide to vote for third-party candidates or withhold their vote in November,” said a statement from the Listen to Georgia Coalition, a group that organized the blank vote campaign. “President Biden must change course now.”

Biden defeated Trump by just 11,779 votes in the 2020 election, a 0.24 percentage point margin of victory.

In Tuesday’s primary, Biden received 95% of votes among three Democratic candidates. Trump won Georgia’s Republican primary with 84% of the vote against 10 rivals.

The blank vote rate was much lower in the Republican primary, where there wasn’t an organized effort to send a message. About 0.13% of Republican primary ballots — or 771 — were blank, compared with the 2.2% of ballots without a vote recorded in the Democratic primary.