Gallego, who left the caucus visibly exasperated, said he would vote against the funding package.

"Last week, I told Nita Lowey specifically that status quo is not acceptable," Gallego said. "I told her today, in this caucus, again, that she'll have to go find Republican votes because I'm not voting for it."

Shortly after the meeting, both the Congressional Hispanic Caucus and the Congressional Progressive Caucus declared formal opposition to the package.

The Hispanic Caucus called it a "blank check" to once again allow Trump to move money from key defense programs to "instead inflict cruelty and militarize our border.”

And the progressive caucus wrote in a statement: "We cannot and will not support more funding for President Trump’s immoral mass detention policies and unchecked and wasteful Pentagon spending."

Still, the angst among the caucus's left flank is far from a rebellion that could take down the spending bill, which would also fund key departments including the Pentagon. Despite the widespread sense of heartburn within the caucus on Homeland Security funding, many Democrats are ultimately expected to vote for the package, which will reach the floor Tuesday.

And as long as Republicans are willing to support the bipartisan spending bills, it will still pass.

"It's going to be a heart wrenching vote for me," Rep. Debbie Mucarsel-Powell (D-Fla.) said in an interview. "But I have to think of so many other people that would be affected if we don't vote for the bill."

The heated debate over immigration funding in the caucus meeting comes after Democratic appropriators huddled privately with the Hispanic Caucus last week in an attempt to ease tensions on the issue.

But both meetings have ended without a resolution for frustrated Hispanic Caucus members who have pushed for months, unsuccessfully, for far stricter rules on Trump's DHS.

Some of the anxiety stems from a painful caucus debate this summer, when many progressive House Democrats were forced to retreat from new provisions to crack down on the White House as part of an emergency border funding bill.

“The Hispanic caucus is not happy,” said Rep. Jan Schakowsky (D-Ill.) as she left the meeting, adding that she hasn’t decided yet how to vote. “The Hispanic caucus was really strong and concerned about not just transferring of money, but deportations and detention beds.”

Democratic appropriators point out that the spending package does, in fact, include some new restrictions on immigration, including a $20 million increase for “enhanced oversight of immigration detention facilities.” It also creates an Immigration Detention ombudsman, who reports directly to the DHS secretary.

“Unfortunately, the President and Senate Republicans insisted on funding a wasteful border wall while simultaneously blocking Democratic policies that would make our immigration system more humane,” Lowey said.

But some Hispanic Caucus members, including Gallego, argued that the provisions are unenforceable, and have also criticized an aspect of the deal that allows certain new fencing beyond the 2017 agreement.

"If we actually had a CR, we would be better off," Gallego said, condemning the fencing provisions. "This allows the $1.3 billion to be placed anywhere, without restrictions."

Heather Caygle contributed to this story.

