Pass a law explicitly forbidding detention of any U.S. citizen without charge, trial, and due process.

From the ACLU.org website: "On December 31, 2011, President Obama signed the National Defense Authorization Act (NDAA), codifying indefinite military detention without charge or trial into law for the first time in American history. The NDAA’s dangerous detention provisions would authorize the president — and all future presidents — to order the military to pick up and indefinitely imprison people captured anywhere in the world, far from any battlefield."

"Although President Obama issued a signing statement saying he had “serious reservations” about the NDAA’s detention provisions, the statement only applies to how his administration would use them, and would not affect how the law is interpreted by subsequent administrations."