A proposal to allow Chicago Police Department officials to impose a curfew anywhere in the city with just 30 minutes notice is set to face a key test Wednesday amid growing concern the measure is unworkable and unconstitutional.

The proposed policy “impermissibly allows officers to use race, ethnicity, and other protected characteristics when making decisions on whether to stop, frisk or search people, in violation of federal and state law,” according to the coalition led by the American Civil Liberties Union of Illinois.

Susan Herman, president of the American Civil Liberties Union, joins us to discuss her book, Taking Liberties: The War on Terror and the Erosion of American Democracy. Read a book excerpt and view a timeline of laws designed to prevent future terrorist attacks.