A group of nearly two dozen GOP senators expressed “grave concerns” with the Department of Homeland Security's deportation review in a letter to President Obama on Thursday.
The 22 senators, including Minority Leader Mitch McConnell (R-Ky.), added that the administration's current policy already shows an "astonishing disregard for the Constitution."
Last month, Obama directed the DHS to review the administration's enforcement of deportation laws to see if they could be made more humane. The Associated Press reported the department is looking into limiting deportations of immigrants living in the country who do not have serious criminal records, among other ideas.
Obama has continuously said there is a limit to what he can do without congressional action.
"Clearly the urgent task facing your administration is to improve immigration enforcement, not to look for new ways to weaken it," the senators said, adding the government is threatened when the administration "suspends the law at its whim."
Immigration advocates and some Democrats have pressed the administration to use its power to slow the rate, similar to a move made in 2012 to deprioritize deportation of children brought to the country illegally.
The senators said the administration's current policies have already made many illegal immigrants "largely exempt from the law." The senators highlighted a recent document that showed Immigration and Customs Enforcement officials last year released 68,000 illegal immigrants with criminal convictions.
"These policies have operated as an effective repeal of duly enacted federal immigration law and exceed the bounds of the Executive Branch's prosecutorial discretion," the senators said.
In addition to McConnell, the letter was signed by GOP Sens. Chuck Grassley (Iowa), David Vitter (La.), Tom Coburn (Okla.), John Boozman (Ark.), Pat Roberts (Kan.), Ted Cruz (Texas), Mike Crapo (Idaho), James Risch (Idaho), Mike Johanns (Neb.), Saxby Chambliss (Ga.), John Hoeven (N.D.), Deb Fischer (Neb.), Richard Shelby (Ala.), James Inhofe (Okla.), Tim Scott (S.C.), Johnny Isakson (Ga.), Mike Lee (Utah), Jeff Sessions (Ala.) and Orrin Hatch (Utah).