(The Center Square) – As President Donald Trump begins his presidency with a flurry of immigration-related executive orders, Republicans are relying on policy experts to back up their claims that drastic change is necessary.

During a House Committee on the Judiciary hearing Wednesday, four immigration experts compared the state of immigration now versus four years ago, with most arguing that the spike in violent crime and drug trafficking over the past four years proves it’s time for a change.

Former ICE field office director John Fabbricatore blasted sanctuary cities in particular as the main cause of the immigration crisis, supporting Trump’s promise to shut them down.

“Sanctuary jurisdictions claim to protect immigrant communities, but they do the opposite. They shelter criminal aliens, accommodating and increasing crimes like drug trafficking, violent assaults, and human trafficking,” Fabbricatore said. “Reversing these policies is not just an option; it’s a necessity.”

He referenced ICE data provided to Congress showing more than 7.5 million illegal immigrants in the U.S. are not in ICE detainment — including nearly 15,000 convicted of murder and more than 20,000 convicted of sexual assault – as of July 2024.

The Drug Enforcement Administration's National Drug Threat Assessment also shows that law enforcement seized 115 million pills containing fentanyl in 2023, more than the six previous years combined.

For Congress to adequately address the crisis, Fabbricatore said, “the bottom line” is for lawmakers to allocate enough money to immigration enforcement agencies to do their jobs and to reinstate neglected interior enforcement rules like ICE detainers.

In response to some Democratic lawmakers on the committee claiming former President Joe Biden did better on the border than Trump, Grant Newman from the Immigration Accountability Project pointed to the raw numbers: under the Biden administration, more than 14 million illegal border crossers have been reported, while under the Trump administration, roughly 3 million illegal border crossers were encountered.

That drastic increase mostly resulted from the previous administration loosening detainment requirements through “catch and release” policies, while simultaneously offering more job visas to illegal immigrants.

“The truth is that the vast majority of illegal aliens are coming here for economic opportunities. If people understand they won't get in, they won't come,” Newman said. “If their friends, family members, NGOs, and cartels can credibly promise an easy path to be released into the United States, they will come. And they have.”

Two major ways that Congress can permanently remove the “job magnet” – no matter who becomes president in the future – are reforming and restricting the parole and asylum processes and ensuring that all employers use E-Verify, he said.

Jessica Vaughan from the Center for Immigration Studies went even further, arguing that some programs, such as the H-2B visa program for seasonal or temporary unskilled laborers, “simply need to be shut down.”

“Over time, our immigration law has become a massive, disorganized menu of entry and work permit programs – some created by Congress, some not – that operates almost on autopilot,” Vaughan said.

She recommended that Congress tighten the issuance of all types of visas, accelerate the removal process, and eliminate the Office of the Immigration Detention Ombudsman, among other things.

But David Bier, testifying for the Cato Institute, said the exact opposite measures are necessary, arguing that the only way to stop mass illegal immigration is by expanding legal immigration channels.

“The available categories for legal immigration are extremely narrow,” Bier’s written testimony noted. “A more effective approach would be to deregulate legal immigration, allowing immigrants to enter as long as they do not pose a security threat and meet other basic criteria.”

Trump “shredded enforcement of U.S. immigration law” during his first term, Bier added, which led to an increase in illegal immigration and criminal migrants entering the United States.

Under the Biden administration, crimes committed by members of the Venezuelan Tren de Aragua prison gang has been reported in at least 22 states, The Center Square reported.

“Do not allow the Left to gaslight you. Secure borders are normal,” U.S. Rep. Wesley Hunt, R-Texas, interjected before the hearing closed. “Every other country would never behave and allow 20 million people to enter their country illegally. That’s not normal.”