A group of Democrats is pushing for Department of Homeland Security Secretary Kirstjen Nielsen to step down, with such calls growing after two heated press appearances on Monday when she declined to apologize for the administration’s family separation practices and falsely blamed Congress for originating the policy.

According to the HuffPost and NBC News, more than 10 Democrats have said that Nielsen should resign, including Sens. Kamala Harris (CA), Dianne Feinstein (CA), Richard Blumenthal (CT), Mazie Hirono (HI), Jeff Merkley (OR), and Tina Smith (MN).

House Minority Leader Nancy Pelosi (CA) and Reps. Barbara Lee (CA), Ted Lieu (CA), Kathleen Rice (NY), and Donald Payne (NJ) have also spoken out. Most of the lawmakers who are ramping up the pressure on Nielsen come from historically blue states and have been vocal critics of Trump’s immigration policies.

Harris — who’s also been a major proponent of preserving DACA protections for young undocumented immigrants — was among the earliest to take a stand on Monday. “The government should be in the business of keeping families together, not tearing them apart. And the government should have a commitment to transparency and accountability,” she said in a statement. “Under Secretary Nielsen’s tenure, the Department of Homeland Security has a track record of neither.”

It’s time for Secretary Nielsen to resign. The government should be keeping families together, not tearing them apart. Add your name to demand her resignation. — Kamala Harris (@KamalaHarris) June 18, 2018

Pelosi made a similar push after paying a visit to a San Diego site where children who’ve been taken from their parents are currently being held. “We have zero tolerance for your neglect and for your policy of selecting — of separating children from their parents,” Pelosi said.

.@SecNielsen must resign. This is not an immigration issue, it is a humanitarian issue. Children are being used by the Trump Admin to create leverage, with a goal of passing Trump’s anti-immigrant agenda. I struggle to think of anything more barbaric. #FamiliesBelongTogether — Nancy Pelosi (@NancyPelosi) June 18, 2018

This rising backlash toward Nielsen comes as outrage continues to build over the Trump administration’s “zero tolerance” policy, under which all adults that enter the US illegally are being prosecuted as criminals, forcing the separation of parents, who are arrested, and their children, who are placed into federal custody.

According to the Department of Homeland Security, nearly 2,000 children were separated from their parents in the span of six weeks.

Nielsen did little to quell critics at two contentious press appearances on Monday, during which she said the administration would “not apologize” for separating families and “doing our job.”

“We have to do our job. We will not apologize for doing our job,” says Homeland Security Secretary Kirstjen Nielsen on separating families at the border. “This administration has a simple message: If you cross the border illegally, we will prosecute you.” https://t.co/NdC1STntVi pic.twitter.com/Be3EMqHlWG — CNN (@CNN) June 18, 2018

As Vox’s Jen Kirby reports, Nielsen has shifted the blame for family separations to Congress, a claim touted by Trump that’s patently untrue.

“Congress and the courts created this problem, and Congress alone can fix it,” Nielsen said at a White House press conference. “Until then, we will enforce every law we have on the books to defend the sovereignty and security of the United States. Those who criticize the enforcement of our laws have offered only one countermeasure: open borders.”

Nielsen, who is responsible for enforcing the family separation policy, has also become its face in recent days — although the New York Times reported that she initially disagreed with Trump about its implementation.

The press conference marked the latest instance when comments she’s made have sparked blowback. Over the weekend, she raised many lawmakers’ hackles after posting a series of tweets arguing that family separation was not, in fact, a Trump administration policy.

We do not have a policy of separating families at the border. Period. — Sec. Kirstjen Nielsen (@SecNielsen) June 17, 2018

Democrats, apparently, have had enough.