It seems that Barack Obama might read the Voice. In the January 23-29 issue ("Barack's Shining Moment?"), I asked why, in Obama's soaring stump speeches, he avoids saying what he would do as president to restore the Constitution after the depredations of the Bush-Cheney regime. If Obama is to be the cavalry rounding up the civil liberties that were rustled by the present administration, he has to remind voters of what their rights are and how they've been stolen.

On February 19, in his victory speech from Houston after winning the Wisconsin primary, Obama pledged: "I will close Guantánamo and restore habeas corpus and say no to torture. . . . [I will be] a president who has taught the Constitution—and believes in the Constitution!"

But if Obama is to go forth against the ever-shifting values of John McCain (who last month voted against a bill passed by Congress that would bar the CIA from torturing prisoners, although he has continually claimed to oppose torture), I would like to recommend a new book for him to read: one that will awaken voters—and hopefully our presidential candidates—to what fundamentally separates us from the jihadists who will be our enemies for generations.

On September 12, 2001, George W. Bush pledged: "We will not allow this enemy to win the war by changing our way of life or restricting our freedoms." But since then, "this enemy" has in some measure accomplished precisely that, as the Bush administration attempts to amass what John MacKenzie calls, in the title of his essential new book, Absolute Power: How the Unitary Executive Theory Is Undermining the Constitution (the Century Foundation Press, available on Amazon).

I have read more than a dozen large books on Bush's conviction that as the commander in chief, he can trump the Congress and the courts and decide by himself what the law says. And I've written and updated this history in my own book, The War on the Bill of Rights and the Gathering Resistance (Seven Stories Press).

But this 77-page paperback, indexed and precisely footnoted, is by far the clearest and most compelling presentation of the war crimes committed by our current leaders (according to the international treaties that this nation has signed), as well as their naked and systemic violations of American laws (such as the widespread eavesdropping on our private communications, which now has the president insisting that the telecommunication companies who broke the law at his behest should be protected from lawsuits by the very Americans whose privacy has been gutted).

MacKenzie had already taught me a lot from 1956 to 1997, when he was a Supreme Court reporter for The Washington Post and then an editorial writer on constitutional issues for The New York Times. To write about the Constitution's continuing battle for survival at home, you have to know a lot about American history, as MacKenzie demonstrates in this book. And this story may surprise you:

"[Alexander] Hamilton, in a six-hour speech to the Constitutional Convention in Philadelphia in 1787, advocated a monarch elected for life. . . . Nobody seconded that motion, and a biographer records that 'he never again uttered a kind word for monarchy.' "

We do not have a monarchy now, but the separation of powers and the other checks and balances built into the 1787 document—as well as the Bill of Rights (of individuals against the government), ratified in 1791—are in severe need of repair.

A crucially important passage in Absolute Power warns against relaxing our constitutional guard merely because the Bush presidency will soon be over. Thanks to the precedents that have been deeply set since 9/11, MacKenzie writes, "The increased potency of the presidency may remain no matter who succeeds Bush, since leaders often are reluctant to yield power, however it may have been derived. . . ."

"[The 'unitary executive' theory launched by the minions of Decider Bush] may remain on the fringes of American life indefinitely. So the unitary executive needs to be understood and resisted with a firmer grasp of the nation's formative ideals and best character."

This could be Barack Obama's job, assuming he wins the nomination and the general election. And if he focuses on this dimension of why he felt the call to be president, we will prove to ourselves—and to the world—that in the end, we did not allow our freedoms to be assaulted from within.

In Absolute Power, there are pointed references to John Yoo, who, while in the Justice Department beginning in 2001, was the chief architect of the boundless "unitary executive" theory. Yoo decreed that in this war against terrorists, the battlefield was everywhere—including inside the United States—and so wherever the president saw danger, Bush could invoke his "inherent" constitutional power to do whatever he considered necessary.

What follows isn't in MacKenzie's book, but I was once present to witness firsthand as John Yoo epitomized the ravening reach of absolute power that must be confronted by the next president and Congress—and the Supreme Court, depending on new vacancies—if the Constitution is to survive.

In April 2005, at Princeton's Woodrow Wilson School of Public and International Affairs, I participated in a panel on "Rethinking the War on Terror." Also at the table was Yoo, who ignored all of my criticisms. At one point, the dean of the school, Anne-Marie Slaughter, a law professor, said to him:

"If I hear you correctly, you [as a government lawyer] would tell your client, the president of the United States, 'You may order pulling out somebody's fingernails. You may order having somebody's family member killed in front of them to extract information. That is constitutional. You are empowered to do that under the Constitution.' Are you really saying that our Constitution allows a president to order that?"

John Yoo replied, "Is there any provision that prevents him from doing that?" (Emphasis added.)

The unitary executive's puppeteer had spoken! Earlier in the debate, Dean Slaughter had strongly denounced the idea that "the president can order the torture of prisoners of war in any way, anytime," saying that such a notion "contravenes absolutely everything this country is supposed to stand for."

It will be up to Barack Obama, if he goes into electoral combat against John McCain, to make the voters ask themselves who we are and what we stand for—and what their president must never stand for, unchecked and unbalanced.

And what are John McCain's views on the separation of powers?