On the heels of a two-day trip to observe immigrant holding facilities at the U.S.-Mexico border, Massachusetts U.S. Rep. Stephen F. Lynch told reporters Sunday that while conditions appear to have improved at U.S. facilities in the month since the last congressional delegation visit, Mexican shelters are now dealing with "serious overcrowding."

"The conditions [in U.S. facilities] are better than what were described initially. The shortage of basic supplies was not observed by any of us," he said. Lynch was one of about two dozen members of Congress who observed several shelters and government facilities in Ciudad Juárez, Mexico, and El Paso, Texas.

Lynch also said U.S. facilities are now less crowded than previously reported, and pointed to the Trump administration's new Migrant Protection Protocols as the likely reason. The policy sends asylum-seekers who arrive in the U.S. on land from Mexico back to the country with "a Notice to Appear for their immigration court hearing," according to the Department of Homeland Security.

"In the facilities that we visited that were so overcrowded and described by my colleagues, those are no longer overcrowded," Lynch said. "A lot of the migrants now are, rather than being cooped up in overcrowded facilities in the U.S., they're back over the border in Mexico."

The result is there is now "serious overcrowding" in Mexican shelters, Lynch said. He added there was concern among the delegation about the pace of the asylum-seekers' pre-hearing review process, which could take several months.

Lynch said he met several women who, after having to leave a U.S. detention center and return to a Mexican holding facility, waited for several months to receive a court hearing before finally returning to their home countries — “mostly Guatemala, Honduras and El Salvador,” he said.

The congressional delegation's trip concluded the day before a gunman opened fire at a packed shopping center in El Paso, leaving 20 people dead and 26 wounded. As of Sunday afternoon, authorities were working to confirm whether the gunman launched an anti-immigrant tirade online before the attack, in their consideration of whether to prosecute the shooting as a hate crime.

Lynch said he did not pick up on widespread anti-immigrant sentiment during the visit, calling the community in El Paso "extremely welcoming and supportive" of immigrants within their community.

"We do have to be as actively and as aggressively engaged in fighting white supremacy as we would any other form of hate crime that is out there," Lynch said.

When asked by a reporter if President Donald Trump contributes to the proliferation of anti-immigrant sentiment, Lynch said he couldn't say there's a "direct causality," but that the president's rhetoric is "not helpful, and probably does feed a certain attitude."

Lynch said the president is driving a focus on immigration in the upcoming presidential election.

"He's using this, obviously as a way to build fear in people, and I think that's how he got elected in the first place," Lynch said. "If people understand the issue more deeply, they'll realize that the way he has characterized immigrants coming to this country is baseless, it is false, it is mean-spirited, is it bigoted and it's wrong."