Texas can ignore President Bush and an international court in refusing to reopen the case of a Mexican on death row for rape and murder, the Supreme Court said Tuesday.

The court said Bush exceeded his authority when he tried to intervene on behalf of Jose Ernesto Medellin, facing the death penalty for killing two teenagers nearly 15 years ago.

The Constitution "allows the president to execute the laws, not make them," Chief Justice John Roberts wrote in a rebuke of the president in a case that mixed presidential power, international relations and the death penalty.

Justice Stephen Breyer, in dissent, said the decision calls into question U.S. obligations under international treaties and makes it "more difficult to negotiate new ones."