The Republican rhetorical assault on so-called sanctuary cities has turned into tangible legislative and bureaucratic action, as the Trump administration and GOP-held legislatures look to punish towns and cities that don’t use their resources to aid in the deportation of undocumented people.

This effort to force local law enforcement to bend to the will of anti-immigration policy makers has been met with resistance from many progressives, though some Democrats—including four in the U.S. Senate—have teamed up with conservatives in opposing jurisdictions expressing solidarity with undocumented people targeted by the Trump-era Immigrations and Customs Enforcement (ICE).

Every GOP senator along with four Senate Democrats—Sens. Joe Manchin (WV), Claire McCaskill (MO), Debbie Stabenow (MI), and Joe Donnelly (IN)—last month voted for the “Stop Dangerous Sanctuary Cities Act,” introduced by Sen. Pat Toomey (R-PA). The vote came amid Senate debate on how to protect people who receive DREAM Act protections from threats by President Trump and GOP lawmakers who have called for the deportation of immigrants brought to the United States as children without documentation.

For the four Democratic senators who joined Republicans in deeming sanctuary cities “dangerous” jurisdictions, this hardly marks the first time they’ve sided with hardline anti-immigrant policy makers, bucking their congressional colleagues and immigration activists in their states fighting to keep undocumented families safe from ICE’s increasingly hostile deportation tactics.

The GOP’s “Stop Dangerous Sanctuary Cities Act,” as introduced last year in the U.S. House of Representatives, “prohibits a sanctuary jurisdiction from receiving grants under certain Economic Development Assistance Programs and the Community Development Block Grant Program,” critical sources of funding.

When law enforcement takes a person into custody, their fingerprints are captured and sent to other agencies, including the Department of Homeland Security. When ICE learns that someone without proper documentation has been taken into custody by local police, the agency will issue what’s known as a detainer request.

A detainer request, which isn’t mandatory, includes a request that “a local jail or other law enforcement agency detain an individual for an additional 48 hours (excluding weekends and holidays) after [their] release date in order to provide ICE agents extra time to decide whether to take the individual into federal custody for removal purposes,” according to the ACLU. 

ICE’s heavy usage of detainer requests “has raised serious constitutional concerns,” according to the ACLU, with the Secretary of Homeland Security in 2014 directing ICE officials to limit their use of detainer requests. In fact, a federal judge in February ruled that holding immigrants using a detainer request constitutes a new arrest, and therefore violates the Fourth Amendment and is unconstitutional. 

Congressional lawmakers, including the four Democrats who voted for the “Stop Dangerous Sanctuary Cities Act,” are demanding local law enforcement officials comply with detainer requests, meaning an undocumented person could be deported for a minor violation. The budgetary punishment for sanctuary city noncompliance would be severe. 

“These policies are a way of assisting the Trump administration [in mass deportations] without affirmatively saying so,” Michael Admirand, senior legal counsel at Harvard Law School’s Fair Punishment Project, told Rewire.News in May 2017.

The offices of McCaskill, Donnelly, Manchin, and Stabenow did not respond to interview requests from Rewire.News.

McCaskill has long been bullish on militarizing the U.S.-Mexico border, joining Republican senators in securing funding for 1,000 new border patrol agents and unmanned aerial vehicles. The top-ranking Democrat on the Senate Homeland Security and Governmental Affairs Committee, McCaskill has advocated for the federal government to prosecute employers who hire people without proper immigration documentation. She has said these employers are “magnets” for undocumented people seeking work.

Erecting roadblocks to the Trump administration’s anti-immigrant plans is hard enough with Republicans controlling both the House and Senate, activists said. Democrats breaking ranks represents a disheartening blow to people on the ground, fighting to protect undocumented families.

“We must unite against [Trump’s] deportation machine. Our strength is in unity, more than ever,” said Alex Martinez, director of the Kansas/Missouri Dream Alliance, a group aiming to educate and provide for undocumented youth. “Our families, brothers, and sisters are continuously being split apart from their families by this racist administration.” McCaskill siding with Senate Republicans is “not surprising really,” Martinez said. The vote “adds to the mounting list of votes that McCaskill has made against protecting our community.”

“Immigrant advocates in Missouri continue to be disappointed with her lack of action,” Martinez continued. McCaskill “should be held accountable for continuously voting with the GOP to deport our families and seeking re-election at the cost of hard working Missourians.”

Donnelly, who has taken the hardline Republican stance of opposing “amnesty” for anyone in the United States without documentation, also supports prosecution of employers who hire undocumented workers. He was given a B grade by Americans for Legal Immigration, an anti-immigration group that opposes resettlement programs that bring Muslim refugees to the United States and—like Trump adviser Stephen Miller—favors a reduction in the number of legal immigrants allowed into the country. Americans for Legal Immigration claims that “thousands” of U.S. citizens are murdered every year by immigrants who came into the country during the Obama administration. The organization’s website features pictures of Hispanic men making lewd gestures.

This from a group that’s largely supportive of a Democratic senator.

Stabenow’s stand against sanctuary cities comes a year after state legislators in Michigan introduced a bill that directed police officers to alert ICE when they have probable cause to believe a person under arrest is undocumented. A leading proponent of the anti-immigrant measure—surrounded by police at a community meeting—was unable to provide Rewire.News with an example of what may constitute probable cause under the bill.

Critics of the Michigan GOP’s legislative assault on sanctuary cities called it “racial profiling” and blatantly unconstitutional. This could be deemed a bipartisan stance, as one of Michigan’s two U.S. senators is also hostile to cities that don’t work hand in hand with ICE to deport anyone in the country without proper documents.

Immigration advocates in Michigan pleaded with state lawmakers last year to rescind the anti-sanctuary city measure. Undocumented families are already afraid for their lives, an activist told Rewire.News.

Manchin, who has signaled support for much of the president’s radical anti-immigration agenda, has received positive reviews from NumbersUSA, which isn’t technically a hate group, but uses racist language like “anchor baby” in its push to limit legal immigration. NumbersUSA is especially smitten with Manchin’s opposition to policies that would bring refugees and asylum seekers to the United States.

These four Democrats are up to re-election in November. If their seats are taken by the GOP, very little will likely change in how those seats side on immigration policy, as activists said in interviews with Rewire.News.

Missouri voters, Martinez said, didn’t elect a Republican when they voted for McCaskill in 2006 and 2012, “but they are getting one. … No need to wait until November.”