On Tuesday, White House officials struggled to explain harrowing images of border agents brutalizing Haitian migrants, facing a growing backlash from outraged Democrats seeking to pressure President Biden to change his immigration policies.

Despite Republican attacks portraying Biden’s policies as weak and ineffective, many immigrant-rights activists have concluded that Biden has failed to live up to his campaign promises to defend vulnerable foreigners seeking a better life in the United States. Their rage represents a new turning point in Biden’s ongoing immigration struggles. In an effort to demonstrate that the administration is taking the matter seriously, Homeland Security Secretary Alejandro Mayorkas said Tuesday that the agents’ activities had been curtailed while they were being investigated.

Immigration has been a source of contention for Biden since his election, and he has privately expressed concerns about being labeled as too lenient by Republicans. After initially relaxing some Trump administration regulations and signaling a more open posture, a surge of migrants arrived at the border, and Biden struggled to house the unaccompanied minors who were among those who arrived. He sparked outrage in his party when he initially refused to raise the annual cap on refugees before eventually agreeing to do so.

Photos and video of border patrolmen on horseback grabbing and shouting at migrants have circulated on the Internet and on television news this week, eliciting stunned reactions from top Democrats. Stories of desperate Haitians sleeping under a border bridge in Del Rio, Texas, only to be turned back have raised safety concerns among many members of the party, who have urged Biden to relax his policies and allow them to enter the country.

The imagery has heightened Democratic outrage over immigration, which was already high after a Senate parliamentarian recently ruled out including a path to citizenship for millions of undocumented immigrants in a massive domestic policy package. While the decision was not unexpected, it forced Democrats to confront the growing possibility that Biden will not deliver the comprehensive immigration reforms that he and his party campaigned on last year.

For many Democrats, this is a particularly bitter blow, given their hopes for a dramatically more humane policy following Trump’s harsh approach to immigration, which included promises of a border wall and a Muslim ban.

Some of Biden’s allies used significantly harsher language about the administration than they had previously.

The NAACP shared two images on Twitter, one of a drawing of a White man about to strike an enslaved Black person and the other of a Border Patrol agent grabbing a migrant. “These images, despite being centuries apart, seem to represent the worst of America’s capacity for humanity,” read the tweet, which went on to urge Biden to take action to “demolish a foundation of oppressive practices.”

Officials in the Biden administration have distanced themselves from the actions of US agents seen in news footage charging at Haitian families and attempting to force them back across the Rio Grande into Mexico.

That didn’t stop top Democrats, including Senate Majority Leader Charles E. Schumer (D-NY), from not only condemning the behavior of US border officers, but also urging Biden to reverse his decision to deport Haitian asylum seekers.

However, the Biden administration shows no signs of relenting. In fact, it is planning to nearly double the number of Haitians deported from Texas beginning Wednesday. Biden is utilizing Title 42 of the United States Public Health Code, which allows authorities to bypass normal immigration proceedings.

Castro noted that the current images are distinct because they appear to reflect a departure from Biden administration policy, which was swiftly condemned by senior officials, whereas family separation was central to Trump’s immigration policy. Nonetheless, he claimed that both sets of images depicted inhumane treatment of migrants.

During a Senate Homeland Security and Governmental Affairs Committee hearing, Mayorkas had to answer to Democrats who were troubled by the images, while Republican senators demanded tougher enforcement and held up poster-size charts showing an increase in illegal border crossings since Biden took office.

The hearing highlighted how Biden has alienated members of both parties by attempting to walk a fine line on immigration, rolling back some of Trump’s hardline policies while maintaining others, such as the use of Title 42.