A month before John McCain is formally anointed as the Republican presidential nominee, his campaign is acting as if Barack Obama is a runaway train that must be derailed at all costs.

Desperation oozes from the latest McCain television ad, equating Obama with celebrity airheads Paris Hilton and Britney Spears as huge crowds before Berlin's Victory monument chant Obama's name during his speech there.

Another McCain ad shows a solitary gas pump with a wildly spinning meter registering the cost, with a mug shot of Obama and a reminder that he opposes drilling off American coastlines. Both ads cast Obama as a slick carnival pitchman, or worse.

Instead, they only underscore his uncommon public appeal and the frenzied McCain campaign effort to burst the Obama bubble. The McCain reaction would seem to be premature, inasmuch as most public-opinion polls indicate he remains well within range of catching up to the perceived runaway train.

Nevertheless, the McCain ads confirm that the presidential race is indeed all about Barack Obama — who he is, what he stands for, and whether he is ready to be president. The Illinois Democrat, for his part, is readily accepting the challenge to fill in the blanks about himself, with good humor so far.

As Obama campaign strategists charge that their rivals have adopted the 2000 and 2004 fear playbook of Karl Rove as Darth Vader, the Democratic candidate himself sloughs off the barbs. He claims the opposition has said he has "a funny name" and "doesn't look like" previous faces on dollar bills.

He wonders before more large crowds why McCain talks about him so much instead of telling more about his own prescriptions for the nation's ills. Of course McCain does that too, but what the television cameras catch and transmit mostly are his anti-Obama remarks.

This apparent dread in the McCain campaign that Obama may be charming his way into the Oval Office has also begun to undermine the Arizona senator's own most appealing qualities of soft-spoken, self-styled "straight talk" delivered in a folksy manner to "my friends."

After years of successful stump speaking in town halls across the country, McCain is often captured by the cameras now reading his speeches from a text stationed before him, and doing it awkwardly and transparently, breaking eye contact with those friends. The contrast with the confidently extemporaneous Obama is strikingly detrimental to the often wooden McCain.

More damaging to him than how he looks, however, is his decision to go AWOL on his pledge to stay on the high road by never questioning his opponent's patriotism. In McCain's attempt to draw his sharp differences with Obama over the war, he has gone overboard in charging that his opponent "would rather lose a war in order to win a political campaign." Even some leading Republicans shot their eyes upward at that one.

In any event, the ground seems to be falling away under McCain on his earlier talk of staying in Iraq as long as it takes to claim victory. His momentary comment, slip or not, that Obama's 16-month troop withdrawal timetable might be OK (depending on conditions on the ground), made him seem to be backing off.

With President Bush himself agreeing with Iraqi Prime Minister Nouri al-Maliki that some "time horizon" may now be in order, and Bush's report that the troop surge of the last year is over and duty tours are being reduced, the war as an issue seems to be fading, before greater concerns over the state of the economy at home.

Here, too, desperation in the McCain campaign seems evident in the candidate's switch favoring offshore oil drilling. It may be a temporary winner with complainers about gas prices. But it's a long-term loser with environmentalists, who continue to trumpet more development of alternative sources of energy.

The latest report that oil giant Exxon Mobil earned a profit of nearly $11.7 billion in its second quarter, the highest take in American history, is certain to persuade many voters that they're being taken to the cleaners at the pump. In all, maybe John McCain does have something to be desperate about so early.

Jules Witcover's latest book, on the Nixon-Agnew relationship, "Very Strange Bedfellows," has just been published by Public Affairs Press. Reach him at juleswitcover@earthlink.net.