Medellín v Texas is a landmark that stands for freedom in the United States.
See United States
In recent years, some members of the U.S. Supreme Court have made attempts to meld U.S. law with foreign law. International norms are apparently a new prism through which U.S. Constitutional law should be interpreted, according to some justices.

For example, in criticizing the Court’s own previous decision upholding state laws against consensual sodomy, the Court stated:
Where a case’s foundations have sustained serious erosion, criticism from other sources is of greater significance. In the United States, criticism of Bowers has been substantial and continuing, disapproving of its reasoning in all respects, not just as to its historical assumptions. And, to the extent Bowers relied on values shared with a wider civilization, the case’s reasoning and holding have been rejected by the European Court of Human Rights, and that other nations have taken action consistent with an affirmation of the protected right of homosexual adults to engage in intimate, consensual conduct. There has been no showing that in this country the governmental interest in circumscribing personal choice is somehow more legitimate or urgent. Lawrence v Texas reversing Bowers v Hardwick
In the Lawrence v Texas decision, the majority opinion focused on global economics and world order as a justification for reversing an opinion that the U.S. Supreme Court delivered seventeen years before.
Medellin is a death penalty case but the Supreme Court did something more important than just deal with the issue of whether the State of Texas must give a psychopath a new trial. In Medellin, the strict-constructionist members of the Court put a death knell to the concept that international tribunals, treaties and legal usages are binding on states like Texas (and the State of Washington). For example, by holding as it did in Medellin– that international treaties and presidential orders do not trump state laws- the Court may have protected Americans from the UN Treaty on Small Arms that the UN is preparing to promote very heavily in the U.S. (the UN has been working on this agenda throughout the world- even as the UN remains a haven for genocidal regimes of every stripe). The “Progressives” who are up in arms against the Roberts Court are livid, according to the Wall Street Journal:
Though the case became a global cause célèbre, its sordid origins trace to 1993, when José Medellín, a Mexican national, murdered two Houston teenagers. He was sentenced to death by a Texas jury, but his lawyers argued on appeal that he hadn’t had access to Mexico’s consulate before he confessed to his crimes.
This was a violation of the 1963 Vienna Convention, which holds that diplomats are supposed to be notified when their nationals are arrested. In response, the U.S. government took steps to ensure states better comply in the future, both to fulfill its treaty obligations and serve the reciprocal interests of U.S. citizens detained abroad.
But Mexican authorities made the case a referendum on capital punishment and international legal norms, ultimately suing the U.S. in the International Court of Justice at The Hague. The ICJ ruled in Mexico’s favor, ordering states to give Medellín and some 51 other nationals new hearings. The question before the Supreme Court was whether such international dictates must be enforced by sovereign state courts. An affirmative answer might have gone a long way toward validating the expansive claims of liberal legal theorists that U.S. courts take instruction from the U.N., among other moral oases.
Chief Justice John Roberts, writing for the 6-3 majority, ruled that the ICJ finding was not binding because the Vienna Convention is an understanding between governments. It is a diplomatic compact that was never intended to automatically create new individual rights enforceable domestically by international bodies. Texas’s violation was of diplomatic protocols, and calls for a diplomatic remedy.
Treaty provisions must be in accord with the plain meaning of the Constitution as it is written, not as some European-style socialists would have it to be. This distinction establishes a fire wall between international and domestic law. It also protects the core American Constitutional principles of federalism and the separation of powers.

Justice Roberts pointed out that courts must leave to the political branches the primary role in deciding when and how international agreements will be enforced.
Medellín v. Texas also swatted away a claim of Presidential power. According to the WSJ, the Bush Administration attempted to calm the diplomatic world by directing states to comply with the ICJ ruling in a 2005 executive order.

The Court ruled that the President’s power is limited by the Constitution. Authority to make treaty commitments does not extend to unilaterally asserting new state responsibilities or legal duties. The executive makes new laws subject to the legislature. The same crowd that is so suspicious of the Bush Administration’s claims of executive power, can’t wait to turn the executive powers over to international politicians who have already banned guns in most of Europe, Australia and Canada, to name a few!
Another safeguard provided by the Medellin case, is the safeguard against potential hate speech laws that chill your First Amendment freedoms. Hate speech laws are being used all over the Western World to silence criticism of Islam. If the multiculturalist crowd has its way, it could become a crime to make statements in the United States of America that violate hate crime laws like the laws enacted in Australia and Canada and many Western European nations. Hopefully we will continue to have Supreme Court Justices that recognize this kind of totalitarianism disguised as multiculturalism as a threat to liberty and free speech.

The Medellín majority has delivered a victory for the U.S. Constitution. For many years, the elite lawyers and politicians have been claiming that the Constitution is always changing based on the needs of each generation. This is not rule of law but an argument for tyranny which would interlineate international norms in place of bedrock Constitutional norms.
There are still many law professors and judges that think treaties supersede the U.S. Constitution. Hopefully the Medellin case has put such legal doctrines to rest! The decision went against the Bush Adminstration this time but if Medellin is reversed the next decision could impose UN-made laws that shut down our ability to conduct full debate on many important issues. Debate is often a strength that promotes new ways of dealing with threats and opportunities.
Ironically, we have President Bush to thank for men like Chief Justice Roberts and the other justices on the Court that read documents in plain English and just said NO to the Bush Administration’s overly aggressive claim of presidential power.
See also Perverting the Bill of Rights.