When Americans are arrested in a foreign country, they have an international right to obtain the help of the US consulate.
The same treaty applies to a citizen of Mexico arrested in the US.
But what happens when the State of Texas ignores these treaty requirements and later rejects an order by President Bush to implement a ruling by the International Court of Justice (ICJ) attempting to enforce the treaty rights?
That's the issue that comes before the US Supreme Court on Wednesday in a case that raises potentially profound questions about the scope of presidential authority to enforce US treaty obligations that clash with the federal-state balance of power and principles of judicial independence.
The dispute stems from a gruesome Texas crime. In 1993, Jose Medellin was arrested for involvement in the gang rape and murder of two teenage girls. The girls, ages 14 and 16, were walking home when Mr. Medellin and his friends ran after and assaulted them. They were killed to prevent them from talking to police.
Medellin was 18 and had spent most of his life in the US. He could read, write, and speak English. But because he was born in Mexico and had never become a US citizen, he had a right to consult Mexican consular officials upon his arrest.
Medellin was represented by court-appointed counsel during his trial, but he did not learn of his right to discuss the case with Mexican officials until after he was sentenced to death for the rape and murder of the two girls.
Lawyers for Medellin raised the issue on appeal, but lost. Then the Mexican government filed suit in the ICJ against the US for failing to provide consular notification and access as required by the treaty.
The ICJ ruled against the US. It ordered that Medellin and 50 other convicted Mexican nationals be given special hearings in American courts to determine if the treaty violation undercut their ability to receive a fair trial.
Although the Bush administration objected to the ICJ ruling, the president later wrote a memorandum ordering the Texas courts to give Medellin a new hearing on the issue. The Texas courts refused, saying Medellin had already received all the process that was required under Texas law.
At the Supreme Court, the justices are set to consider whether Mr. Bush acted within his authority as president when he ordered the state courts to conduct a new hearing in the Medellin case to comply with the ICJ ruling.
Lawyers for Medellin say the president acted well within his powers.
"When a nation enters into a treaty, it undertakes an international obligation that binds all of its organs (executive, legislative, and judicial) and all its constituent jurisdictions (state and federal)," Donald Donovan writes in his brief to the court on behalf of Medellin.
"By binding itself to comply with a judgment of the ICJ in a case to which it was a party, the United States bound all the states, including Texas, and all its judicial organs, including the Texas courts," Mr. Donovan writes.
Texas Solicitor General R. Ted Cruz has a different view. "This is a separation of powers case," he says in his brief. "It implicates every axis of the structural limitations on government."
Mr. Cruz adds, "The presidential memorandum [ordering the rehearing], transgresses the authority of Congress, of the judiciary, and of the states."
Medellin v. Texas represents a clash between the faithful enforcement of an international treaty by the president and the faithful enforcement of Texas state law by Texas state judges. Under the current set of facts there is no compromise.
One must yield to the other.
The ICJ requires the Texas courts to take an extra step – and hold an extra hearing – to determine whether the treaty violation undercut the fairness of Medellin's trial. Texas law says that once certain issues are resolved in a criminal case, they shall not be reargued.
Solicitor General Paul Clement agrees with a portion of the Texas argument – that the treaty grants no individual power to Medellin to enforce the treaty. But Mr. Clement goes on in his brief to assert that Bush does have the power necessary to order the state courts to provide a meaningful remedy for Medellin.
"When the president acts pursuant to a duly ratified treaty and his own constitutional authority, he acts with the full authority of the United States, and his authority is at its zenith," Clement writes.
Cruz, the Texas solicitor general, responds that because Bush's memo clashes with so many other powers in the US, he must first obtain the approval of Congress to properly authorize his chosen remedy.
"There are constitutional avenues available," Cruz says.
Among them, according to Cruz, Bush could ask Congress to pass a special amendment to the federal habeas corpus statute to permit an additional level of appeals in the federal courts to satisfy the ICJ ruling. Or the president, in concert with the Senate, could enact a treaty with Mexico requiring additional review of the ICJ cases in federal court, he says.
The alternative, Cruz says, is that the president's order to the Texas judiciary be viewed as a mere request, rather than a presidential command.