America Is Better Than This: Senator Jeff Merkley's book on refugees to be published in August
The publisher is calling America Is Better Than This a "cry of outrage."
Merkley, an Oregon Democrat, made headlines when he travelled to Texas in 2018 and streamed his efforts to gain entry to a migrant facility.
He has become a prominent critic of the Trump administration's immigration policies and has introduced the Shut Down Child Prison Camps Act.
America Is Better Than This will be published Aug. 20 by Twelve, an imprint of Grand Central Publishing.
In a statement Tuesday, Merkley said the country is at a moment when it might abandon its dream of "opportunity for everyone" or renew its commitment for "a better nation and better world."