On Dec. 13, a federal judge dismissed the habeas corpus petition of Salim Ahmed Hamdan, a detainee at Guantanamo Bay, Cuba. Latin for “you have the body,” habeas corpus allows detainees to ask a court to order their warden to explain the basis for their detention. Hamdan’s petition was dismissed because of the Military Commissions Act, which Congress passed last fall to take away the habeas rights of Guantanamo Bay detainees. The MCA is a classic example of “jurisdiction stripping.” When the courts hand down rulings that Congress doesn’t like, lawmakers sometimes retaliate by trying to take away their power to hear certain kinds of cases, or by strictly limiting what they can do.

That is also the story behind another case, in which the Supreme Court reversed a lower court’s decision to grant a new trial in a murder case. At the original trial, the victim’s family members wore large buttons with his picture on them, which the U.S. Court of Appeals for the 9th Circuit ruled violated the rights of the defendant, Mathew Musladin. Musladin brought a habeas corpus petition arguing that the buttons could have prejudiced the jury. Most of the Supreme Court justices agreed that seeing the victim’s picture every day didn’t exactly dispose the jury to be more fair. But the federal courts could not intervene, they ruled unanimously, because of a 1996 statute that allows them to give habeas relief only when the state courts have gotten the law utterly wrong.

Why does Congress get to take cases away from judges? In his book “America’s Constitution,” Yale law professor Akhil Reed Amar points out that judges weren’t the heroes of the revolution. They were appointed by the British crown. The Constitution’s drafters gave Congress weapons to use against the courts without giving judges much to defend themselves with. The president can draw his veto pen if Congress goes after him. The Supreme Court has to find a straight-faced way to declare a law unconstitutional when it weakens the judiciary’s powers, Amar writes.

The MCA is such a law. It also may be unconstitutional in some cases. But Hamdan’s case isn’t one of them, according to last week’s ruling by U.S. District Judge James Robertson. Hamdan’s problem is that he’s a non-citizen whose contact with the United States has been “involuntary.” The MCA stripped Hamdan of the right to habeas corpus granted by federal statute. There are also constitutional rights to habeas. But non-citizens don’t have the sort of “substantial connection with our country” that justifies invoking the constitutional right to habeas corpus, the Supreme Court ruled in 1990 in United States v. Verdugo-Urquidez.

If Robertson is right that this ruling applies to Hamdan – a question the Supreme Court will eventually settle – hundreds of Guantanamo Bay detainees won’t get federal habeas review either.

The limitations of habeas review, in the wake of Congress’ tinkering, are on display in cases such as Musladin’s. The legislation that Congress passed in 1996 says that the federal courts can’t grant a habeas petition that state courts have turned down unless the state court decision “was contrary to, or involved an unreasonable application of, clearly established Federal law, as determined by the Supreme Court.” That is a high bar. The ruling in Musladin’s case underscores how high: The 9th Circuit was wrong to spend its time determining whether it was fair for the victim’s family to wear the photo buttons in front of the jury. Instead, the federal courts can only look to see whether the Supreme Court has already said it’s not fair.

There are reasons for federal judges to defer to state judges – among them the principle of comity, according to which different branches of government show respect for one another, and the principle of finality, which in this context basically means that you get your habeas crack in the state courts, and that’s enough. But habeas review has historically given defendants a chance to air their appeals outside the state system, with its giant caseloads and sometimes rushed rulings. Congress’ 1996 habeas law has largely choked off this avenue. Consider Justice Anthony Kennedy’s concurrence in Musladin’s appeal. “Buttons proclaiming a message relevant to the case ought to be prohibited as a matter of course,” he wrote, and called for a new rule to make it so – in a future case. In other words, too late for Mathew Musladin.

If Musladin’s predicament doesn’t move you, consider that of Paul Gregory House. Twenty years ago, a Tennessee jury convicted him of a woman’s murder after FBI testing appeared to show his semen on her clothing and her blood on his jeans. He was sentenced to death.

Then DNA testing showed that the semen on the victim’s clothes came from her husband, and that the blood on House’s jeans came from autopsy samples that spilled in the crime lab. Whoops. But House still had a big problem: His claims of innocence were barred by state procedural rules. Would the federal courts pry open the doors?

It was hardly a slam-dunk. Last June, in a dissent by Chief Justice John G. Roberts Jr., four justices said that the courts need not reconsider House’s appeal, because he had not proved his innocence. But five justices said that House should get his second day in court because he had shown that it was likely that no reasonable juror would find him guilty beyond a reasonable doubt.

Even so, House doesn’t get out of prison, nor is he spared the death penalty. He doesn’t automatically get a new trial. Because of the 1996 habeas law, he has to plunge back into the procedural thicket.

Letting Congress strip the courts of the authority to hear certain claims or cases means giving more power to the people, who can elect their lawmakers but not their federal judges. From a pre-revolutionary vantage point, that made sense. But these days it’s more often judges whom we can count on, if we can count on anyone, to stand up for the procedural rights of murder defendants and Guantanamo Bay detainees. Should Congress be able to block them?