Amy Coney Barrett and Neal Kaytal at the Constitution Center:
The Suspension Clause protects liberty by protecting the privilege of the writ of habeas corpus. It provides that the federal government may not suspend this privilege except in extraordinary circumstances: when a rebellion or invasion occurs and the public safety requires it.
...
The Clause does not specify which branch of government has the authority to suspend the privilege of the writ, but most agree that only Congress can do it. President Abraham Lincoln provoked controversy by suspending the privilege of his own accord during the Civil War, but Congress largely extinguished challenges to his authority by enacting a statute permitting suspension. On every other occasion, the executive has proceeded only after first securing congressional authorization. The writ of habeas corpus has been suspended four times since the Constitution was ratified: throughout the entire country during the Civil War; in eleven South Carolina counties overrun by the Ku Klux Klan during Reconstruction; in two provinces of the Philippines during a 1905 insurrection; and in Hawaii after the bombing of Pearl Harbor.
