Amid outrage over Immigration and Customs Enforcement operations under President Donald Trump's leadership, Congress is considering capping the number of beds available in ICE detention centers. The idea is that such a measure would slow the crackdown on illegal immigration, which in many cases, is uprooting and separating families that have lived peacefully in the United States for decades.

But according to two prominent law enforcement organizations, implementing detention ceilings would have disastrous impacts for American communities.

What could happen?

In a letter to Congress last week — which was obtained by the Daily Caller — the National Sheriffs' Association and Major County Sheriffs of America warned that capping the number of beds available in ICE detention centers would result in the release of thousands of convicted criminal illegal immigrants.

"Any legislation that reduces ICE's detention capacity would hinder its ability to perform its national security and public safety missions, but also impact local law enfocements [sic] ability to protect the communities they serve. In order to meet the cap being tentatively proposed by Congress, ICE would be compelled to release thousands of aliens from custody," the letter warned.

To achieve the proposed cap of 16,500 adult detainees, ICE would be required to release 9,264 adults. This is concerning, the law enforcement organizations said, because 72 percent of ICE's current detainee population is "subject to mandatory detention due to the alien having certain convictions or having committed certain acts."

Also, more than 90 percent of ICE arrests constitute illegal immigrants with existing criminal convictions — not illegal immigrants whose only offense is living in the U.S. illegally.

"Capping the number of detention beds utilized by ICE not only jeopardizes the integrity of the immigration system, but would cripple ICE's ability to detain criminal aliens and other aliens who pose a risk to public safety or are a flight risk," the letter explained.

What is Congress considering?

As part of nuanced negotiations to prevent a government shutdown last December, lawmakers discussed limiting ICE detention centers for only immigrants apprehended by the Border Patrol.

Negotiations stalled during the government shutdown in December and January, but have begun again in hopes of crafting an immigration deal to prevent another government shutdown, the Washington Examiner reported.

A shutdown looms because Trump demands Congress finance a border wall while Democrats, who control the House, refuse to appropriate the funds for such a project.