It’s not just about the economy or the wars in Iraq & Afghanistan. It’s also about the Supreme Court. Here’s Gary Wills writing in the New York Review of Books.

When Charles Gibson was questioning Governor Palin, he should not have asked about the Bush Doctrine (a wavering concept, and touching only one matter, war). He should have asked for her views on the unitary executive—the question Cheney asked the Court nominees. That is what matters most to the Bush people. It affects all the executive usurpations of the last seven years—not only the right of the president to wage undeclared wars, but his right to create military courts, to authorize extraordinary renditions, secret prisons, more severely coercive interrogation, trials with undisclosed evidence, domestic surveillance, and the overriding of congressional oversight in every aspect of government from energy policy to health services.

All these policies were driven by the unitary executive theory of the Constitution, which emanated from David Addington in Vice President Cheney’s office. Charlie Savage has documented that four Supreme Court justices are already enthusiastic supporters of the unitary theory—Roberts, Alito, Scalia, and Thomas.[16] It takes only a fifth justice to solder that theory into place for the foreseeable future. This would be the most thorough reworking and distortion of the Constitution in all our history.

The stakes are staggering. That is why the Republicans are so desperate to win this year. If they fail, not only will their previous encroachments be endangered, but the investigation of illegal acts will be removed from protection by presidential veto. Nothing short of wholesale pardons by the outgoing president can give many people cover for acts they undertook on the assurance that the unitary executive was exempt from congressional action. This prospect is so terrifying that John McCain has taken over the thuggish tactics that defeated him in 2000. The Republicans have everything to lose.

The unitary executive theory was elaborated in Edwin Meese’s Justice Department under Ronald Reagan. In its first form, it asserted that Congress can have nothing to do with an agency once it has set it up. Everything after that is an executive task, and only the president can determine executive personnel and conduct.

Wills thinks that “There is something terrifying in the fact that a sweeping presidential power … is now accepted by four of the nine Supreme Court justices. Add a fifth justice to them, and the Constitution will be under the severest siege in its history. There can be no higher stakes.”

He’s right.