From the Los Angeles Times on Wednesday, Aug. 26:

On inauguration day, a new U.S. president is a demigod, the embodiment of aspirations as vast as they are varied. Over the course of the years that follow, the president inevitably fails to fulfill those hopes. So the cycle begins anew, and Americans look to the next occupant of the Oval Office to undo his predecessor's mistakes and usher in an era of lasting peace and sustained prosperity.

Yet Sen. John McCain's campaign hardly has been shy about fostering grandiose expectations. Speaking earlier this month, while most Americans were fretting about the cost of oil, McCain uncorked one of his patented straight-talking promises: "I'm going to lead our nation to energy independence." As far as McCain would have us believe, you can take that to the bank.

Will the next president actually bring about Big Change? Don't get your hopes up.

Regardless of who wins on Nov. 4, we should temper our expectations of what George W. Bush's successor will accomplish, especially on foreign policy.

In reality, presidents don't make policy; administrations do. To judge by the cadre of advisers they've recruited, neither candidate holds much affinity for outside-the-box thinkers. Obama's "national security working group," for example, consists chiefly of Democratic war horses, including former secretaries of State Madeleine Albright and Warren Christopher and former national security adviser Anthony Lake -- a group that is not young, not charismatic and not known for innovative thinking.

McCain's national security team features a strong neoconservative presence, including pundits Max Boot and Robert Kagan, along with hawkish Washington insiders Randy Scheunemann and James Woolsey. All figured prominently among advocates of invading Iraq; none has yet to repent. Agents of change? Not likely, unless having a go at Iran qualifies as creative thinking.

The very structure of American politics imposes its own constraints. For all the clout that presidents have accrued since World War II, their prerogatives remain limited. A President McCain almost certainly would face a Congress controlled by a Democratic and therefore obstreperous majority. A President Obama, even if his own party runs the Senate and House, wouldn't enjoy all that much more latitude, especially when it comes to three areas in which the dead hand of the past weighs most heavily: defense policy, energy policy and the Arab-Israeli peace process.

Then there is the growing gap between American power and the demands of exercising global leadership.

In matters of substance, Big Change will remain elusive. The next president will leave his own imprint on U.S. policy. It just won't be nearly as distinctive or dramatic as the most enthusiastic Obama and McCain supporters have talked themselves into expecting.