Nevada Rep. Susie Lee was one of 26 House Democrats to vote for a background check amendment that would alert Immigration and Customs Enforcement if an undocumented immigrant attempts to purchase a firearm.

The amendment was part of the “Bipartisan Background Checks Act of 2019” a bill Democrats have called the most significant gun control measure in more than two decades. Only eight Republicans voted for the final version of the bill, which passed largely along party lines with a 240-190 margin. But before that vote, Republicans filed a “motion to recommit”, adding in language that directs law enforcement officials to notify ICE if an “illegal alien” attempts to purchase a firearm by going through the process of application.

“It is already illegal for undocumented individuals to purchase or possess a firearm, and this vote reinforces that,” said Lee press secretary Renzo Olivari in a statement on supporting the amendment. “But most importantly, the House passed the most significant gun safety legislation in decades, and did so on a bipartisan basis.”

In a closed-door meeting the day after the vote, House Speaker Nancy Pelosi admonished wayward Democrats arguing that they must stick together on procedural votes, according to Politico.

“We are either a team or we’re not, and we have to make that decision,” she said.

New York Rep. Jerry Nadler called the amendment a “total red herring” that would “mix up the immigration issue with the gun violence issue” and had “nothing to do with the purpose of the bill,” while Rhode Island Rep. David Cicilline said the amendment was a “phony issue to try to muck [the bill] up with this gimmick,” according to the congressional record.

New York Rep. Alexandria Ocasio-Cortez told reporters she believed the Republican amendment was “an extension of Trump’s tactics into the House.”

“We cannot legitimize it and we cannot allow for it and we cannot support it,” said Ocasio-Cortez, according to Politico.

Politico also reported that Pelosi warned her caucus that vulnerable Democrats who had the “courage” to vote along with the Democratic party on difficult votes would have a higher priority for party leadership and the Democratic Congressional Campaign Committee (DCCC), a fundraising program that offers structural support in re-election campaigns.

In early February Lee was added to the DCCC’s “Frontline” campaign program which aims to support vulnerable Democrats in swing congressional districts.

Most of the Democrats who voted for the bill represented districts President Donald Trump won in 2016. Clark County was carried by Democratic presidential candidate Hilary Clinton in 2016, but Trump narrowly carried District 3, the district Lee represents. The district has more registered Democrats than Republicans, about 180,00 to 170,000 respectfully. But the district also has roughly 115,000 nonpartisan voters, along with about 21,000 registered in the Independent American Party, a group well know to vote along Republican lines.

Lee’s victory was the first time since Congressional District 3 was created following the 2000 census that a Democrat won the seat in a midterm election.

During House debate over the Republican motion, Rep. Doug Collins, R-GA, who offered the amendment, appealed to Democrats in swing districts, telling them “If you vote ‘no’ on this motion to recommit, you cannot go back to your constituency, no matter what is said, and say: ‘I voted to keep illegal aliens, those who should not have a firearm, from having a firearm.’”

In Las Vegas, immigration advocates have been pushing to scale back the reach of ICE in their communities. Last month, activist groups along with Clark County Commissioner Tick Segerblom protested outside the Las Vegas Metropolitan Police Department after filing an open records request seeking details and data about Metro’s controversial 287(g) detention policy agreement with U.S. Immigration and Customs Enforcement (ICE).

The 287(g) agreement allows the Department of Homeland Security to enter into voluntary agreements to authorize local law enforcement agencies to assist in immigration enforcement. In practice, police can detain non-U.S. citizens — even on an unpaid traffic ticket warrant — until ICE takes custody, which can lead to possible deportation proceedings for undocumented immigrants.