Robert Scheer is the publisher of Truthdig, where this article originally appeared. His new book, The Pornography of Power: How Defense Hawks Hijacked 9/11 and Weakened America, will be published June 9 by Twelve.

Will the real John McCain stand up? Actually, I don’t expect him to, now that he is the Republican presidential candidate, pandering to the irrationalities that drive his party. Nor is it likely that the fawning mass media will pressure him to the point of clarity. But I remain genuinely confused as to what makes him tick.

McCain is the most confounding of candidates, veering as he does from the stance of provincial reaction to sophisticated enlightenment within an almost instantaneous time frame. He did it last week, when he blasted Barack Obama for being soft in appraising America’s adversaries while in the same moment, calling for sensible rapprochement with Vladimir Putin’s Russia on nuclear arms control. While such unpredictability can be appealing in a senator, it is unnerving in a possible President.

Unpredictability is welcome as evidence of fresh thinking, but not when it suggests inconsistencies that may be born more of crass opportunism than of insight. There are major contradictions in the McCain America has witnessed over the years that are truly troubling.

One is squaring the Mr.-Clean-of-the-Senate McCain, who teamed up with the remarkably principled Democrat Russ Feingold to sponsor historic campaign finance legislation, with the McCain who has brought big-money lobbyists into the center of his Senate office and campaign operation. Those connections with the Beltway bandits remind one that McCain was previously one of the “Keating Five”–senators whose support of deregulation, a code word for undermining legitimate government oversight of business shenanigans–facilitated the savings-and-loan crisis of the 1980s and ’90s. Not a happy association, at a time when the consequences of bank deregulation surfaces as the subprime mortgage lending scandal that is wrecking the US economy.

Then there is the heroic-warrior McCain, who rose above his own wounds to team up with fellow Vietnam War hero, Democrat John Kerry, to pave the way for normalization of relations with Vietnam. McCain had the courage to reach out to Hanoi, despite a very strong domestic opposition that accused him of betraying the MIAs left behind in Vietnam by negotiating with the former enemy. The subsequent progress on that issue, where US teams could more freely investigate plane crash sites in Vietnam, vindicated McCain, who has favored other diplomatic overtures, including a controversial suggestion of meeting with Hamas. Yet he now attacks Obama for saying he would meet with the leaders of Iran.

On a related point, it is difficult to square the ex-POW’s unequivocal condemnation of torture with his accommodation to President Bush’s torture policy. Holding Senate hearings on torture, McCain brought the weight of his own experiences against the Administration’s flimsy rationalizations. He even held to that principled position during the early primaries, but then ended up voting for legislation that has helped make torture legal, at least in the eyes of the President.

The third major gap between the principled-Senator McCain and the presidential candidate McCain concerns his stance toward the military-industrial complex that has seized upon the fearmongering in post 9/11 America to justify the biggest peacetime military budget in any nation’s history. As a senator, McCain was a rare and forceful voice against enormous waste in the military budget for programs designed to fight an enemy that no longer existed and which could not be justified in the name of fighting terrorism. Thanks in part to McCain’s vigilance, a defense contracting scandal he exposed resulted in a Pentagon procurement officer and the CFO of Boeing being sentenced to federal prison, when it was revealed that the Air Force was leasing unneeded air tankers at an initial cost of $30 billion.

It was not the first time that McCain had risen on the Senate floor to accuse the Pentagon of being in cahoots with defense industry lobbyists, and he does deserve high marks for being one of the few members of Congress willing to hold the military-industrial complex accountable. But we hear little from that McCain these days as he goes on and on praising a pointless war in Iraq that has become the main excuse for wasting trillions in so-called defense dollars.

This last is the deal breaker. It is simply not possible to be a genuine small-government-give-taxpayers-a-break President while planning to pour trillions more down the rat hole of failed imperial adventures.