In a veto last weekend, President Bush once again approved past and future use of torture in the interrogation of terrorist suspects. The bill would have outlawed the CIA’s use of waterboarding, or simulated drowning, and other techniques prohibited by the military and law enforcement agencies. Supporters of the torture ban, including both of Maine’s Republican senators and both Democratic representatives, were a strong majority in both houses, but neither tally met the two-thirds requirement to override a veto.

Mr. Bush argued that what he called “specialized interrogation procedures” were essential in extracting secrets from captured terrorists. But he was ignoring advice from the FBI and other agencies, whose officials have testified that the extreme methods are unnecessary and counterproductive. And commanding Gen. David H. Petraeus, in a statement last May to the troops in Iraq, said: “Some may argue that we would be more effective if we sanctioned torture or other expedient methods to obtain information from the enemy. They would be wrong. Beyond the basic fact that such actions are illegal, history shows that they also are frequently neither useful nor necessary. Certainly, extreme physical action can make someone ‘talk,’ however, what the individual says may be of questionable value. In fact, our experience in applying the interrogation standards laid out in the Army Field Manual on Human Intelligence Collector Operations that was published last year shows that the techniques in the manual work effectively and humanely in eliciting information from detainees.”

All this is questionable enough from the point of view of practical governance and America’s standing and reputation in the world. But it is also part of a deliberate effort by the Bush administration to concentrate all federal government power in the executive branch. This little-known doctrine called the Unitary Executive Theory is said to have originated in the 1980s in the Reagan administration. Right-wing think tanks and legal societies formulated it, and Vice President Dick Cheney led the way in implementing it as the central strategy of the Bush administration.

The theory lies behind the administration redefinition of torture to permit waterboarding, its political firing of eight state U.S. chief prosecutors, its wiretapping of American citizens, its suspension of the historic right of habeas corpus and its policy of preemptive warfare against presumed threats – all under the blanket justification of the “war against terror.”

Mr. Bush had used the doctrine 95 times by 2005, as counted by professor Christopher Kelley of Miami University in Oxford, Ohio.

A new history and analysis of the doctrine by John P. MacKenzie, “Absolute Power: How the Unitary Executive Theory Is Undermining the Constitution,” warns that at least three Supreme Court justices support it and that a sometimes subservient Congress often goes along with it.

As a new national election approaches, voters should beware of Mr. MacKenzie’s warning that the Bush power grab could extend into the next presidency: “Presidents do not easily surrender authority, even if they recognize that the authority was illegitimately claimed.”