On Monday, the White House would not rule out suspending habeas corpus ahead of the approach of a migrant caravan to the US border.
Suspending habeas corpus is seen as a move that could allow thousands of migrants participating in the caravan from Central America to the US border to be detained indefinitely without a hearing.
While the suspension of habeas corpus is rare, it is not unprecedented.
RELATED: Trump to send the military to the southern border
Reporters asked White House Press Secretary Sarah Sanders if President Donald Trump would suspend habeas corpus. Sanders said in response, "We're looking at a number of different options."
What is habeas corpus
In simple terms, it means people (citizens and noncitizens) can seek recourse to go before a judge while being held in detention in the US. Those who believe they have been unfairly detained can petition for a writ of habeas corpus. A successful petition means the those who are holding a suspect must bring the suspect before a judge to have the suspect's detainment adjudicated.
Article 1, Section 9 of the US Constitution states, "The privilege of the writ of habeas corpus shall not be suspended, unless when in cases of rebellion or invasion the public safety may require it."
This law should not be confused with the Sixth Amendment of the US Constitution, which makes it a right for a speedy trial.
It is also not a right against unlawful arrests, but a right to be released after an illegal arrest.
History of suspending habeas corpus
While rare, there have been attempts by presidents to suspend the writ of habeas corpus in the past. One notable instance came during the Civil War when President Abraham Lincoln attempted to suspend habeas corpus.
In the case Ex Parte Merryman, a US federal court ruled that Lincoln did not have the right to suspend the writ of habeas corpus. Maryland's John Merryman, who was a backer of the Confederate government, petitioned for a hearing following his arrest. Federal courts, led by Supreme Court Justice Roger B. Taney, found that only Congress could suspend habeas corpus.
Lincoln's government ultimately defied the order, and Merryman never faced a judge while detained.
A year later, Congress passed a measure that would give Lincoln the authority to suspend the writ of habeas corpus as long as the Civil War was ongoing. The suspension of habeas corpus remained in effect until Dec. 1, 1865.
Habeas corpus was examined again following the Sept. 11, 2001 attacks on America, as President George W. Bush attempted to hold those suspected of being connected to terrorism without a hearing. In Hamdi v. Rumsfeld, this executive order was overturned by federal courts.
In 2009, President Barack Obama declared in an executive order that enemy combatants held by the US have the right to a writ of habeas corpus.
What does this mean for the caravan?
While attempted by presidents in the past, federal court precedent would likely indicate that for habeas corpus to be suspended, Congress would have to sign off on it. Habeas corpus is under Article 1 of the constitution, which spells out powers of Congress.
Trump's language might also influence the decision on whether to suspend habeas corpus. In a tweet on Monday, Trump said, "This is an invasion of our Country and our Military is waiting for you!" An "invasion," as Trump puts it, would justify Congress to enact a suspension of habeas corpus.
That would also mean federal courts would also have to agree with Trump that the caravan is indeed an invasion of the US.
One caveat to the invasion argument is it is expected that members of the caravan will seek asylum in the US rather than cross the border illegally. Seeking refuge is legal under both US and international law.
The House of Representatives and Senate are expected to return to Washington on Nov. 13, which should still be well before the arrival of the caravan.