CHICAGO (CBS) — With the inauguration fast approaching, the American Civil Liberties Union has expressed concerns president-elect Donald Trump might infringe upon constitutional freedoms after taking office.

Ask ACLU Illinois executive director Colleen Connell what concerns she has about a Trump presidency, and her answer is immediate.

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“A lot,” she said. “We are concerned about individual civil liberties, as well as the president-elect’s apparent lack of understanding for the structural limits that the constitution imposes on governmental power.”

Trump’s proposals for a Muslim registry and mass deportations of undocumented immigrants in particular have the ACLU worried about what he might do in office.

David Applegate, an attorney with the conservative Federalist Society, a group of conservative and libertarian lawyers and judges, said they share concerns about executive overreach, but he doesn’t think Trump will be able to do everything he has proposed.

“Trump supporters tend to take Trump seriously, but not literally; and Trump detractors tend to take him literally, but not seriously,” he said.

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Applegate said there is a system of checks and balances in the federal government to limit presidential authority.

“Article I, Section 8 vests the entire lawmaking power of the federal government in the people, speaking through their Congress. The executive branch is to see that the laws are faithfully executed,” he said.

Connell noted the Republican-controlled Congress has not been kind to progressive concerns.

“I think that those of us who give serious credence to what Mister Trump says are right to be concerned,” she said.

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Trump and the U.S. Constitution are the focus of this week’s edition of “At Issue,” airing Sunday at 9:30 p.m. on WBBM Newsradio 780 and 105.9FM.