Final answer:
The Supreme Court's 2008 ruling in Boumediene v. Bush granted detainees at Guantánamo Bay the right to challenge their detention in U.S. courts, overturning the Military Commissions Act of 2006.
Step-by-step explanation:
The significance of the Supreme Court's 2008 ruling in Boumediene v. Bush was that foreign terrorism suspects held at Guantánamo Bay have the constitutional right to challenge their detention in United States courts. The Supreme Court's 2008 ruling in Boumediene v. Bush granted detainees at Guantánamo Bay the right to challenge their detention in U.S. courts, overturning the Military Commissions Act of 2006.
This ruling granted detainees at Guantánamo Bay the habeas corpus right to go to federal court to challenge their detention, thereby giving them access to the U.S. legal system and protection under the Constitution. It overturned the Military Commissions Act of 2006, which had removed the federal courts' jurisdiction over habeas corpus applications from enemy combatants.