While John McCain’s latest boomlet in the news media seems to threaten the fledgling campaigns of his party’s other White House hopefuls, the presumed front-runner for the Republican nomination could be peaking too soon.

The senior senator from Arizona still has the right stuff when it comes to luring cameras and reporters into following his wake, as they did for his pivotal role in the immigration debate and for his recent rapprochement with Christian evangelist Jerry Falwell. Fulfilling his reputation for playing political wild cards, McCain hewed to the left on immigration, joining forces with Democratic Sen. Edward M. Kennedy of Massachusetts to champion a guest worker program, while almost simultaneously tacking rightward by agreeing to speak at Falwell’s ultra-conservative Liberty University.

As the only Republican who gave George W. Bush a scare in the GOP presidential primaries six years ago, starting with his surprise victory in New Hampshire, the 69-year-old former prisoner of war has every right to stake a claim for the 2008 party nod. And the news media’s fondness for him, encouraged by his genial accessibility to them, serves to establish McCain as the Republican to watch in the next White House race.

But you have to wonder if there is something of an illusion about McCain’s latest moment in the spotlight. The stunning meltdown of Bush’s popularity in opinion polls has created a power vacuum in Republican politics that only an exceedingly well-known and aggressive self-promoter such as McCain could fill. Other GOP presidential contenders, such as Gov. Mitt Romney of Massachusetts, Sen. Bill Frist of Tennessee and Sen. George Allen of Virginia, are still in the process of introducing themselves to the nation.

McCain all but stands alone as the Republican with the national track record and name recognition to be the president’s stand-in for keeping the public’s faith in his party. Still, he could be only a transitional figure, much like the 79-year-old Pope Benedict XVI, whose election last year was widely seen as a consensus choice for keeping the faith until the next generation of Catholic leadership emerges.

But unlike the new pope, who seems to shy away from the world stage, McCain is the king of all media in his domain. The political risk is that by the time the presidential trail heats up late next year, he could be old news to Republican voters ready for new faces.

After years of near-universal power in Washington, there is a chance that Republicans might use the 2008 campaign as a rebuilding season for the future, content to groom new leaders even if it means losing an election. Big thinkers in GOP circles privately admit a bit of fatalism about having run their course in the natural cycle of American politics, seeing the next cycle or two as likely to usher in a period of Democratic Party resurgence.

As this thinking goes, the move for the GOP over the long term could be seeking to maintain a shaky grip on the White House with an aging politician such as McCain. (He’ll be 72 in 2008.) While such dark notions might soon lighten up, this is the sort of soul-searching that Bush’s demise has prompted among party strategists.

McCain is certainly doing his best to assume the role of party leader. In some ways, he is playing Bush’s traditional scripts as the president desperately tries to remake himself. He chose to dwell on a spirited defense of the war in Iraq for his May 13 commencement address at Falwell’s university in Lynchburg, Va., while less than two weeks later Bush was taking back his tough war words in a news conference with British Prime Minister Tony Blair. The president expressed regret for once taunting terrorists with the words “bring it on” and “wanted, dead or alive,” adding that “not everything has turned out the way we hoped” in Iraq.

And McCain’s effort to make peace with Falwell, whose influence on party politics he denounced as “evil” in the 2000 campaign, was clearly aimed at tip-toeing into Bush’s now-vacant shoes as the leading Republican darling of Christian evangelicals. The right-leaning maneuver may cost McCain the adoration he had long attracted among many Democrats and independents, but appealing to non-Republicans in a general election is not his greatest need at the moment. He must soften opposition among die-hard social conservatives who dominate party primaries if he is to have even a prayer of a chance of winning the nomination.

Despite his machinations, McCain could find that his media savvy does not automatically convert into party primary votes, as happened in March’s straw ballot among Tennessee Republicans. Seeing that he had little chance to win, McCain encouraged a write-in campaign for Bush. In what might have been a prophesy for the coming White House campaign, McCain’s clever tactic garnered more attention from news reporters and pundits than from the voters who ultimately choose winners and losers.

Contributing Editor Craig Crawford is a news analyst for MSNBC, CNBC and “The Early Show” on CBS. He can be reached at ccrawford@cq.com.