Kennedy Moves Front and Center on Court

In the most divisive cases before the court in the term that just ended, it was Justice Anthony M. Kennedy who determined the outcome every time. In unpredictable fashion, he sided some of the time with the court's conservative bloc and some of the time with its liberals.

His influence was dramatically displayed Thursday, when the court announced that it had struck down President Bush's specially created military tribunals for suspected terrorists.

As Justices Antonin Scalia and Clarence Thomas read their dissenting opinions in court that day, Roberts and Samuel A. Alito Jr., Bush's other new appointee, could do no more than listen in agreement.

It was 86-year-old John Paul Stevens, the court's last World War II veteran, who read the 5-3 majority opinion. He solemnly declared that the president was "bound to comply with the rule of law" and that he could not ignore congressional mandates and long-standing U.S military rules.

He paused to note that Kennedy, seated next to him, had joined most of his opinion, creating a majority. Liberals hailed the result, and conservatives lamented it.

While the issue before the court was the balance of power in government, the drama showed how little the balance of power within the high court itself had changed. Even when Roberts and Alito side with fellow conservatives Scalia and Thomas, they need a fifth vote to prevail.

For the last decade, Justices Kennedy and Sandra Day O'Connor, both Ronald Reagan appointees, had supplied the votes that decided the court's major cases. They usually joined with the conservatives on issues of crime, the death penalty, civil rights and states' rights, but with the liberals on abortion, gay rights and school prayer.

Now, with O'Connor in retirement, Kennedy stands alone at the center.

He voted with the conservatives more often than not, but joined the liberals in several major rulings. In one closely watched environmental case, Kennedy wrote a separate, solo opinion that was decisive.

On the issue of military tribunals, Kennedy made it clear that he shared the liberals' concern about unchecked presidential power.

The Constitution created "a system where the single power of the executive is checked," he wrote. Even in a national emergency, he said, "the Constitution is best preserved by a reliance on standards tested over time and insulated from the pressure of the moment."