David Hogg has slammed any Democrat who supports deeper U.S. involvement in the conflict between Israel and Iran, saying anyone who does "needs to be primaried."
In a post on X, a former vice chair of the Democratic National Committee, pointed to the cost of previous wars in Iraq and Afghanistan.
"Our generation grew up going through two multi trillion dollar wars we should have never been involved in," Hogg wrote on Monday. "We are not f going back to that. If you think this is a good idea read a history book."
Newsweek has contacted Hogg and the Democratic Party for comment via messages and emails sent outside regular business hours.
Hogg, a gun control activist, was removed from his role as vice chair of the Democratic National Committee following a clash with leadership over his plan to raise money for progressive candidates challenging Democratic incumbents in safely blue districts.
The infighting in the party comes as Democrats are seeking to rebuild ahead of the 2026 midterm elections after losing power to President Donald Trump in November's election.
Meanwhile, direct U.S. involvement in the Israel-Iran conflict could also anger Trump supporters who were buoyed by his promise to end the nation's involvement in expensive foreign wars.
Hogg said that Democrats must present a united front against Trump, who on Monday warned Tehran's citizens to evacuate as he cut short his trip to Canada for a Group of Seven summit tor return to Washington for talks with his national security team.
In another post, Hogg questioned the silence of lawmakers who usually oppose high government spending.
"Where are all the 'we can't afford it' politicians now that we're on the brink of what could be another multi trillion-dollar war?" he wrote.
Hogg, who rose to national prominence as a gun control advocate after surviving the 2018 shooting at Marjory Stoneman Douglas High School in Parkland, Florida, became a DNC vice chair in a February election. The DNC removed him following a complaint over gender parity, saying the election had not followed the party rules. Hogg said he would not run in redo elections.
His removal came after he announced that his political action committee (PAC), Leaders We Deserve, would invest some $20 million to support primary challengers against incumbent Democrats in safely blue districts.
On Monday, Democratic Senator Tim Kaine of Virginia, a member of the Senate Armed Services and Foreign Relations Committees, introduced a resolution to require that Trump first seek authorization from Congress before using military force against Iran.
The conflict between Israel and Iran entered a fifth day on Tuesday, and Trump has backed Israeli strikes.
"Iran should have signed the 'deal' I told them to sign," Trump wrote on Truth Social on Monday night.
"IRAN CAN NOT HAVE A NUCLEAR WEAPON," he wrote, adding that "everyone should immediately evacuate Tehran!"
The president was expected to arrive at the White House early on Tuesday. He told reporters as he left Canada and the G7 summit that he would be monitoring developments in the Middle East from the Situation Room, according to CBS News' Jennifer Jacobs.
He later wrote that French President Emmanuel Macron was wrong to say the U.S. was working on a ceasefire, saying his reason for returning to Washington early was "much bigger than that."
"American Forces are maintaining their defensive posture & that has not changed," Sean Parnell wrote in a post on X. "We will protect American troops & our interests."
The conflict began with Friday's surprise Israeli attack on Iran's military and nuclear program. Israel said its assault on Iran's top military leaders, uranium enrichment sites and nuclear scientists, is necessary to prevent its longtime foe from getting any closer to building an atomic weapon. Israel's strikes have killed at least 224 people since Friday.
Iran has retaliated by launching more than 370 missiles and hundreds of drones at Israel. So far, 24 people in Israel have been killed and more than 500 injured.
Iran maintains its nuclear program is peaceful. The U.S. and others had recently assessed that Tehran had not had an organized effort to pursue a nuclear weapon since 2003. The head of the International Atomic Energy Agency has repeatedly warned that the country has enough enriched uranium to make several nuclear bombs should it choose to do so.
David Hogg wrote on X: "Democrats must be united against Trump and his war. We can't f* this up."
President Donald Trump told ABC News on Sunday that "it's possible" the U.S. becomes involved in the conflict between Iran and Israel.
He said: "We're not involved in it. It's possible we could get involved. But we are not at this moment involved."
Senator Tim Kaine said in a statement on Monday: "It is not in our national security interest to get into a war with Iran unless that war is absolutely necessary to defend the United States. I am deeply concerned that the recent escalation of hostilities between Israel and Iran could quickly pull the United States into another endless conflict.
"The American people have no interest in sending servicemembers to fight another forever war in the Middle East. This resolution will ensure that if we decide to place our nation's men and women in uniform into harm's way, we will have a debate and vote on it in Congress."
Defense Secretary Pete Hegseth told Fox News' Jesse Watters on Monday that "of course" Trump wanted to see a deal made to curb Iran's nuclear program.
He said: "His position has not changed. What you're watching in real time is peace through strength and America first. Our job is to be strong. We are postured defensively in the region to be strong in pursuit of a peace deal. And we certainly hope that's what happens here. And America first means we're going to defend American personnel and American interests. So when you see jets and you see air defense assets and counter-UAS assets, that's because my job as the Secretary of Defense is to ensure that our people are safe and that we're strong."
The latest talks between the U.S. and Iran were canceled over the weekend.
On Sunday, Tehran said that Iran would stop its strikes if Israel does the same. On Monday, Iran's foreign minister, Abbas Araghchi, appeared to make a veiled outreach for the U.S. to step in and negotiate an end to hostilities between Israel and Iran.