A pro-Israel rally on the Boston Common on Monday signaled a potential schism within the Democratic Party over how best to respond to the ongoing war between Israel and Hamas, as Sen. Ed Markey (D-MA) was booed for calling for de-escalation between Israel and Hamas.

“Hamas wants continued instability, not normalization. They are violent extremists. They gain support when there is a crisis,” Markey said. “That is why the United States and the international community must keep pushing for diplomacy and the ending of civilian casualties on all sides. There must be a de-escalation of the current violence.”

Markey’s call for de-escalation prompted loud boos from the crowd, including a chant of “it’s not equal” from someone in the crowd. 

The rally, which featured Markey, Sen. Elizabeth Warren (D-MA), Rep. Jake Auchincloss (D-MA), Massachusetts Gov. Maura Healey, State Treasurer Deborah Goldberg and Boston Mayor Michelle Wu as speakers, was organized by the Combined Jewish Philanthropies of Greater Boston, Boston Jewish Community Relations Council, Israeli American Council and the local Israeli consulate.

Auchincloss, who spoke minutes after Markey, elicited loud cheers from the crowd for comments explicitly rejecting de-escalation — an apparent repudiation of Markey’s remarks.

“This will be a hard war. Israel needs the support of its most important ally, the United States,” Auchincloss said. “Israel needs moral support from Americans. Now is not the time for equivocation. Hamas is an internationally recognized terrorist organization that is executing and raping civilians. Israel is a liberal democracy with the right and responsibility to defend itself and its citizens. De-escalation is not possible when [Hamas] are taking hostages.”

“Israel did not ask America to de-escalate on Sept. 12, 2001,” Auchincloss continued, invoking comparisons between the Hamas attack and the Sept. 11, 2001 terror attack on the U.S.

The juxtaposition between the comments by Markey, a progressive who’s been more critical of Israel’s policy toward the Palestinians, and Auchincloss, a pro-Israel moderate, could signal coming divides in the Democratic Party over how best to respond to the ongoing war — support for Israel’s own counteroffensive or for mutual de-escalation and diplomacy — particularly once Israel’s ground assault on Gaza begins.

But in a sign of the strong support that Israel continues to see across the political spectrum in the U.S., Warren, a staunch progressive who has in the past floated the possibility of restricting aid to Israel, delivered a tearful speech offering strong support for the Jewish state.

“I’m here today to say unequivocally, there is no justification for terrorism ever,” Warren said. “I am here to grieve with you. I am here to stand in solidarity. But standing in solidarity does not mean standing still. Standing in solidarity means action. It means shouldering the obligations of a strong and faithful ally.”

Warren continued, “As a member of the Armed Services Committee, I am committed to Israel’s safety and security,” endorsing President Joe Biden’s statements of “full support” to Israel. She went on to call for former Treasury Secretary Jack Lew’s prompt confirmation as the next U.S. ambassador to Israel and for the approval of the more than 300 military promotions being held by Sen. Tommy Tuberville (R-AL).

“Our job is to reaffirm to Israel and reaffirm to people all around the world that America will be a steadfast ally,” Warren said. “We pray for peace. We care for each other. And we ready ourselves for the challenges ahead.”

Auchincloss also called on House Republicans to “jettison their extremists to enable bipartisan governance,” describing the House as “paralyzed” by the lack of an elected speaker.

Jewish Insider’s Washington correspondent Gabby Deutch and reporter Tori Bergel contributed reporting.