A group of 20 Senate Democrats on Monday sent a letter to Senate Appropriations Committee Chairman Richard Shelby (R-AL) and Vice Chairman Patrick Leahy (D-VT) and Subcommittee on Homeland Security Chairman Shelley Moore Capito (R-WV) and Ranking Member Jon Tester (D-MT) asking the leaders to reject President Trump's 2020 Department of Homeland Security funding.

Specifically, the Democrats want to keep DHS from seeing additional funding for Immigration and Customs Enforcement (ICE) agents and beds and construction of the border wall. In fact, they want funding decreased for beds in detention facilities.

"The immigration detention system is plagued by limited oversight and accountability and inhumane conditions. Federal oversight bodies have identified extreme management shortcomings, including deficient contracting policies and a lack of reasonable inspections," the letter said. "ICE immigration detention facilities and ICE contractors often fail to comply with ICE’s own set of performance-based standards of care for detainees, and ICE does not have systems in place to provide for the comprehensive correction of deficiencies."

The group wants to limit the number of additional ICE personnel because the agency "has set a record for arrests of undocumented immigrants with no criminal record—arresting an average of 4,219 undocumented immigrants without a criminal record for each month of the Trump administration."

According to the Senators, Trump's border wall would be ineffective.

"A border wall would do little to aid drug interdiction efforts, as the majority of narcotics entering the U.S. from Mexico by land move primarily through our ports—a fact confirmed by DHS and the U.S. Drug Enforcement Agency. Instead, supporting the use of new technologies to monitor border crossings at ports-of-entry represents a better investment in border security," the letter read.

The group also claimed Trump manufactured the crisis on the border and they "cannot justify spending taxpayer dollars on an ineffective wall."

The letter was signed by Sens. Robert Menendez (D-NJ), Dianne Feinstein (D-CA), Kamala Harris (D-CA), Dick Durbin (D-IL), Bernie Sanders (I-VT), Amy Klobuchar (D-MN), Jeff Merkley (D-OR), Michael Bennet (D-CO), Kirsten Gillbrand (D-NY), Richard Blumenthal (D-CT), Tammy Baldwin (D-WI), Mazie Hirono (D-HI), Elizabeth Warren (D-MA), Ed Markey (D-MA), Cory Booker (D-NJ), Chris Van Hollen (D-MD), Tammy Duckworth (D-IL), Catherine Cortez Masto (D-NV), and Jacky Rosen (D-NV).

Here's the full letter: